I wasn't aware of home hi-fi but British gear for musicians was widespread when I was growing up (Marshall, Vox, etc).
I was specifically thinking of the components my father got through the Army PX in the 60s and the hi-fi gear I would see at some friends' houses in the decades that followed ... sometimes tech that never really took hold, such as reel-to-reel audio. Most of it was Japanese, and sometimes German.
I still have a pair of his 1967 Sansui speakers in the basement (one with a blown woofer, unfortunately) and a working Yamaha natural sound receiver sitting next to my desk from about a decade later.
Whoa there! Audio components were about the only thing the British still excelled at by that time.