IIRC normal workers are supported (dedicated workers) but shared workers are not. Service workers are "supported" but some features that are pretty critical (like push notifications) are not.
I believe this is the other thread: https://news.ycombinator.com/item?id=29440457
Re:Web Workers API
by rubyskills on Saturday December 04, 2021 @09:57AM
(#29441203)
Also I think push notifications are not supported.
One point was, web workers aren't supported correctly.