Wrong: Chrome based extensions come far behind in the number and breadth of functionality that legacy Firefox accumulated over the years. In totality it cannot even match the functionality that Tab Mix Plus provided ( PC World said that "With Tab Mix Plus, Firefox tabs go past the obvious and into the indispensable... it's hard to imagine how you lived without it.") along with Colorful Tabs. Show me the Chrome extension than enables multiple tab rows, or adjusts max or min tab width, or even a simple option like enabling Ctrl+Tab to toggle btwn more recently opened tabs, rather than the ridiculous through all tabs (there is an extension that is sppsd to do this but apparently it does not do that, but sets up alternative keys, and I have not figured it out yet). Or adds Copy Url on the right click menu for a inactive tab. Or that keeps the Find bar open across all tabs, Or any of the other functions I listed (and there are more), with the possible exception of the Open With extension I found.
Hidden Chrome option that enables stacked tabs.
chrome://flags/#stacked-tab-strip
I have used and liked TabsOutliner. Why would I want 300 tabs open? To me that means one is doing something wrong. Prefer to have tabs that are open, or bookmarked, or grouped in a side window, all easily visible and accessible. Can make that side window any size I want.
So you are comparing the number of extensions for an OLD, legacy version of Firefox. Firefox is up to version 85. Many of those extension don't work on the new version that started in version 57. You really want to stay stuck on an old antiquated browser?