As another example, the Path of Exile community moved off onto their own community-run wiki domain, but the Fandom variant (which is woefully out of date) continues to be one of the top results when searching for a PoE wiki page.

In some regards that's inevitable, but it clearly shows what Fandom's priorities are.

Fandom purchasing Gamepedia and moving everything onto Fandom Wikia was so awful. I'm so upset the Dota2 Gamepedia wiki is now on Fandom, and I'm sure many other communities feel that way for their own community run and community led wiki pages.

Not that I was particularly warm about Gamepedia either, but at the bare minimum I didn't feel like the page was all ads and no information. Fandom wikis are explicitly set-up to drive as many eyeballs as possible onto advertising and engagement, and are holding actually relevant information for the visitor as a hostage to get those eyeballs. It's information masquerading as a social media site.

The Runescape community convincing Jagex to cover the hosting costs and moving all their wiki pages to their own set-up has been such a huge boon for their community. It is super unfortunate that for many communities, the community-led wiki pages are a huge trove of information but the companies/games/groups these communities coalesce around have shown little to no interest in merely just financially supporting the endeavor.

The key difference between manifest V2.0 and V3.0 with regards to uBO is in V2, the extension has direct access to the browser's process in making web requests and can make direct changes to those requests. V3 instead requires the extension to declare a list of urls and the browser will act on the extension's behalf. This is a very simplified explanation that isn't in any meaningful depth and misses a ton of nuance.

The outcome though is V3 makes it significantly more difficult for uBO to achieve its goals for its users. It is a downright and explicit downgrade, and when Chrome fully moves to Manifest V3.0, uBO's ability to serve its core functions will likely be diminished.