I use Firefox because it works fine and doesn't appear to be trying to exploit me.
I don't know what "WebExtensions" are or how they differ from regular extensions, but if Firefox breaks all the adblockers and scriptblockers that I depend on to make the web tolerable, I'm going to have to downgrade that "works fine" rating.
WebExtensions are going to look a lot like Chrome's extensions, to the point that many addons will be compatible between the two. So, speaking loosely, anything Chrome addons can do now will be supported.
I don't know what "WebExtensions" are or how they differ from regular extensions, but if Firefox breaks all the adblockers and scriptblockers that I depend on to make the web tolerable, I'm going to have to downgrade that "works fine" rating.