In Firefox there's a reader view which allows to read some web pages without all the distracting ads and other stuff. And often enough, it circumvents annoying pop-ups that force you to sign-up or login before you can read a page.

I couldn't find it, or am I missing something here? Are there possibly some extensions that can make that work?

    Matth Yes Vanadium does have this feature.

    Go to Vanadium > 3 dots > Settings > Accessibility and enable the toggle 'Simplified view for webpages'.

    When you open an article in Vanadium, a pop-up will now ask if you want to view the simplified webpage (reader view).

    Another option to read articles simplified without pop-ups/ads is by using an RSS client.