On M1/M2 Macs, Miro still kinda/sorta works. But it throws a minor crash error at startup and visibly hasn't kept up with web standards. It hasn't been updated since 2013. There's no sign of any further update. Three of its no-longer-supported components are 32-bit.
Same as the last reviewer, the icon matches the 'Miro' I use (a collaboration/whiteboard tool), but this isn't that app, and means with every update I get my Miro replaced with this video player.