Depending on what your performance target is, you might do without adapters. Low speed USB can be bitbanged even with 8-bit attiny. RP2040 with PIO can run DV

Depending on what your performance target is, you might do without adapters. Low speed USB can be bitbanged even with 8-bit attiny. RP2040 with PIO can run DVI, 720p@30Hz (though you do need to overclock the chip heavily). I don't know how to implement Ethernet with digital logic (it uses pulse amplitude modulation) but bandwidth-wise it's not too challenging. Gigabit signals to PHY are 125MHz using RGMII. I think 100Mbit Ethernet would use 25MHz but I'm not actually sure. All doable using commodity microcontrollers without an FPGA. I could see a long road to a dystopia where these legacy protocols are deprecated and they push out devices that only speak new protocols that won't let unapproved devices talk.. but I'm not that pessimistic. I can't see the copyright mafia chasing things down so far, and they'd rail up against all the industrial users.