The brilliant people that stayed in the USSR had no choice - they were kept there by force either directly (not allowed to leave) or indirectly (leave but your family will pay the price).
But they all wanted to leave. The more you knew how much better your life could be in the west, the more you hated staying.
See, I don't know if that's true. The main counter evidence to your hypothesis were the defections of scientists and engineers to the USSR, the amount of brilliant people that regretted the fall of the USSR, and so on.
For example, one of my brilliant math teachers was from a Soviet state, and had the opportunity to leave all along - he only did so as the USSR fell and he did not see any prospect in the East anymore.
Patriotism is a strong emotion. But beyond that, many brilliant people in communist countries really did enjoy a very elevated social status - if you see what children aspired too, being a scientist or engineer was really up there. And as far as job security and research freedom, for example, there was often quite a bit of it. On the other hand, you had drastically less freedom, but it doesn't seem the ones who chose to stay valued it as much as we would.
See, I know that is true. I was unlucky enough to grow up behind the iron curtain. I know the situation directly from the choices faced by my parents and their friends and after its fall I watched the best of my teachers slowly but surely emigrate to Canada or the Western Europe.
You can't really understand how it was unless you lived it. First of all, patriotism ceased to exist, except for propaganda. Struggle and fear - abject fear - replaced patriotism as the driving emotion. We ended up hating our country - we're still trying to re-learn how to love it 30 years later.
The ones in elevated status were collaborating with the authorities and the secret police. They ratted out on their friends and family. Everybody hated and feared them because of that.
The freedom was, of course, gone, and we got used to that. Freedom is just not that important when you're hungry. But the feeling that best described our state of mind then was: hopelessness. We did not, could not hope for a better future, for better times for us or our children. We could not see any escape, any chance at change. Because as individuals, there was nothing we could do. We were completely robbed of our agency, of our power, of our rights. The past, present and future was a single color: gray.
People who somehow went to the West came back changed. They just could not believe one could live with so much freedom, choices and wealth. Their stories inspired others. I was maybe 12 and I remember clearly dreaming up ways of running out of the country, to my father's absolute horror. I would cry rivers if my own children would have to go to through that.
The issue is, you're just someone on the internet. The real people I know disagree with you, and so do statistics, so while I completely empathize with you, I can't agree.
Use your logic then. Ask yourself who was defecting where. Ask yourself who had a the better level of life and who had the gulags. Ask yourself why so many countries and their hundred of millions of inhabitants violently overthrew the communist regime at the end of the '80s.
Better yet, go ahead and pay a visit to the communist success stories of N Korea, Cuba or Venezuela. They are still around. Maybe they will convince you.
Then finally look around at the very tools you are using. The car you are driving, the furnace heating your house, the computer you write on. They are all success stories of capitalism. Ask yourself where are the success stories of communism. What things it built, what hard, concrete, useful stuff it created. Believe the proof presented to you by the real world - and reject the propaganda.
The majority of the citizens of the USSR were against its dissolution - but that didn't matter, it was mostly an elite affair.
I look at statistics and what people that I know and lived there told me. Most people who were adults at the time seem to regret the fall of the Soviet Union, and most people from post-Soviet states had to leave when they couldn't make a living anymore as the economy collapsed - despite post Soviet states being squarely in the middle of what you can expect from life on earth and above the median in all relevant metrics.
So certainly, it wasn't perfect, but it was very far from hell on earth, and squarely above the middle.
Your argument would also be stronger if you didn't classify Venezuela, a country with a bigger private sector relatively than France, as a communist country - Cuba, I've went there, was far from bad, much better certainly than where I came from, and despite debilitating American sanctions has a GDP PPP of over 21000$ which is quite impressive and above the average for the world, let alone Latin America, and by far the best of any country sanctioned by the US, and North Korea abandoned communism for a long time for their own "Juché" ideology which is basically Strasserism, preaches the superiority of the Korean race, and now allows private markets too.
Your stories are also quite telling - the computer I'm using was only possible under capitalism because the government gave itself the power to control ideas, as capitalism is otherwise incompatible with large-scale intellectual innovation. I drive no car, as it is far inferior to good quality public transportation plus walkable neighborhood, and my house is electrically heated by 100% renewable energy because we had the good sense of nationalizing the power grid and making massive investments in renewable energy (which we now produce at costs lower than any free market of energy, renewable or not).
The actual evidence when I try to look it at critically, shielding myself from all forms of propaganda (in the classical sense of the word), makes it clear that reality is far more nuanced than is common wisdom in these circles, and one of those results after careful study of history and data is that the USSR did not, in fact, have much of an issue retaining engineers and scientists, and relative to its size and prosperity did an okay job at innovating and keeping its population happy. Far from the best, but much better than most.
But they all wanted to leave. The more you knew how much better your life could be in the west, the more you hated staying.