What's the liktlyhood of ~~a technical~~ any audience being 4 days behind on updates? (hint: very high)
Not me keeping Chrome open for two months with "New Chrome available" badge in the corner.
My 58 Firefox tabs that get updated once every 30-60 days when i reboot my desktop lolol
None of which means you should expect your audience to have a new version which came out three days ago. Lots of technical people stay behind the bleeding edge for very good reason.
This is why I added the wasm fallback. The question was why I didn't serve PNGs to everyone.