Comment by chrismorgan

Note that when you say “rejected”, Mozilla’s position has actually shifted a bit. At the end of 2022, it shipped MIDI in the form of an extension that it will prompt to install for the purpose, with more detailed information and a couple of other details that make it less unsafe. After a few years of that, consensus has grown that this seems to be working acceptably, and that the technique may be considered for other risky areas. They haven’t said anything about USB publicly, to my knowledge, which is definitely way more dangerous than MIDI (even SysEx), but I have heard one rumour (of dubious provenance) that they may cautiously proceed with USB and such too some time soon. Though this sort of thing definitely weighs against that, showing that maybe they were right the first time.