[jeroenhd]

With Firefox's market share, not much. This could massively benefit Firefox adoption, though, because everyone relying on old extensions will have to switch.

From that viewpoint, the new restrictions could actually be a good thing.

[chihuahua]

At the point when Edge (Chromium) no longer supports proper adblockers, I would instantly stop using it and use Firefox for almost everything. It would be a 100% deal-breaker for me. Right now, I have Firefox installed but don't use it much, because I don't see a compelling advantage.

[AnonC]

If you start using Firefox now, you may probably better appreciate it (especially if you also look at other features and extensions like Containers).