Tree Style Tabs is a must for me. It makes the tab/tab goup functionality in other browsers feel awful.

Tab Session Manager

Is there anything that disables / stops sticky videos when scrolling on mobile?

I get pissed off when I'm reading a news article, scroll down, and their headline video (often just an ad) clips itself to the top 1/3 of the screen.

AdNauseam. An AdBlocker that also creates a trail of Garbage Data to make users less valuable for Advertisers and Data Collection

In general:

• Bypass Paywalls
• Dark Reader
• HTTPS Everywhere
• I don't care about Cookies
• Karrinator
• KeePassXC Browser
• NoScript
• Simple Tab Groups
• Tampermonkey
• UBlock
• UnloadTabs (Vor allem für Müll wie MS Teams)
• User Agent Switcher and Manager
• Vencord
• Video Download Helper

For YouTube:

• AutoReplay for YouTube
• Disable YouTube Seek by Number
• Return YouTube Dislike
• SponsorBlock

Most of those Addons are for me to not go insane or blind.

Aside from the popular ublock origin I'd get Sponsor Block. Too bad my mobile version doesn't support it.

Tab Stash.

Others have already mentioned some excellent vertical tab add-ons, so I'll post Tabs Aside, which is a super convenient way to save and load a window full of tabs. Saves having like 20 windows open with different stuff you don't want to lose.

Lots of great extensions have been listed already, but here's one that I haven't seen mentioned yet and I really like: https://unhook.app/

uBlock Origin and Mouse Gestures.

Literally all I have ever used. I love mouse gestures so much because of Opera. I was using that for a bit before I discovered Firefox back in the day.

Ever since Twitch Now stopped working, I found Gumbo which is working really well.

Stylus has been a pretty newish one for me, been using it a lot to make Lemmy feeds wider and take up my entire screen

There's also a convert webp to anything extension that is really handy to have

Video download helper is cool too