For a while now the transition away from Manifest V2 (MV2) to MV3 has been on-going and it looks like it is entering its final phase of deprecation, at least, in the case of Google Chrome. A recent discussion thread in the w3c WebExtensions Community Group GitHub repo has highlighted how the latest and upcoming versions of the most popular browser are expected to be its final releases with support for MV2 extensions.
What this essentially means is that the tricks and bypasses that were used to keep MV2 extensions like uBlock Origin and others alive will not work any more on Chrome, or at least not for very long. For example the Windows Registry mod that could extend MV2 availability will cease to function after Chromium version 151.
Bookmarks in mobile Firefox is another issue. Bookmark management is a massive chore. I end up keeping tabs around a lot longer in mobile just to avoid messing with it.
On desktop Firefox with the Bookmark Tab Here extension (native functionality I missed from Chrome), bookmarking and organizing a new page is just two clicks. I use that workflow extensively. Apparently I have over 7000 bookmarks all organized that way.