Legitimate question here: Is there a legit reason to Firefox over Chrome at this point? I mean, its not performance, its not convenience, and now its not even privacy. At this rate, it looks like Firefox is going to end up just like Chrome, but slower and less fully featured.
Manifest V2/V3 is a reason to still use Firefox.
There are still a lot of differences between the two browsers and a monoculture is still bad.
How ever I see the pull towards Chromium.
Well, they would be holding back the web, if they had significant marketshare.
Personally at my job we dropped Firefox support. I imagine we're not the only ones to do so.
1. Chrome/Chromium's performance only recently became acceptable in 2022 when the Chromium team finally added support for tab discarding, many years after Firefox first had this feature. Tab discarding is essential for users who regularly have hundreds of tabs open. The Chromium team has historically not given a fuck about such users.
2. Firefox is vastly more configurable and extensible than Chrome/Chromium. For example, Tree Style Tab and Sidebery are far better for managing hundreds of open tabs than Tabs Outliner, the closest alternative for Chrome/Chromium. This difference, like the one above, is mostly relevant to power users.
Given that 20 years have passed since Firefox was first released, and 99.99% of web users nowadays are casuals who never have more than a couple tabs open and would sooner kill themselves than learn about the many useful ways Firefox can be configured via about:config, user.js, userChrome.css, userContent.css, etc., the answer to your question is probably no.
I use Firefox simply because the address bar UX is better. It prioritizes my history over search results, I almost never have more than 3-5 tabs open, so I rely heavily on typing a keyword in the address bar to go to a page in my history.
Another thing I rely a lot is Multi-Account containers, which makes it very to keep aspects of life separated.