The browser didn't mention anything about reading/writing/modifying content of all sites? It's been a minute since I've messed with browser extensions, but I remember the ability to write 'tags' to a site's content was gated behind a permission dialog during "installation".

I think the browser telling you what an extension is technically capable of is different to the extension letting you know what it’ll be doing and why.

Installing my adblocking extension the browser told me the app is capable of reading all web pages and editing them, but I assume they aren’t using that capability to track me.

>they never asked

often there are shady "by using this service ..." type clauses in the most obscure places. I've even seen them in black text on a black background and only noticed because my mouse ran past it and I noticed the change.

Yeah that's not what asking means.