It figures that Realtek is a key part of the story. The availability of Realtek PHYs and NICs is what's finally allowing 2.5GbE and 5GbE to go mainstream for consumer equipment. Aquantia got bought by Marvell and ended up with enterprise-level pricing on all their stuff. Intel completely tanked their reputation for NICs with a few failed attempts to implement 2.5GbE support, and haven't even tried to introduce a consumer-grade 5GbE option. But now that Realtek is in the game, 2.5GbE is widespread in new desktop motherboards and fairly cheap in USB Ethernet adapters.