Something like this is probably want you need. This one costs money but I'm not sure if there's a free one.
Firefox
A community for discussion about Mozilla Firefox.
I don't get why people are so resistant to using bookmarks. This is literally their purpose.
This isn't a hard problem. Nobody needs to keep 400 tabs open. You aren't reading them all at the same time.
Bookmarks are synchronized, grouped by folders, and don't disappear unless deleted.
You can open an entire folder with a couple taps. You can switch between tabs with a couple taps or a swipe on the toolbar.
I can see a problem with bookmarking for things such as comics, manga, series, etc
The url changes between each episode/chapter, so you would've to remove the previous bookmark and add the new one, which is a hassle if you read a lot of stuff (my case)
I used to have an addon for this exact scenario that would auto-update the bookmarks as I read. It may have been this one, but it doesn't appear to support mobile.
The issue with bookmarks is that it takes too much navigation to open one and browsers don't allow to select multiple in a folder to open
Firefox on Android allows selecting multiple bookmarks or a folder to open all at once, and its 3 taps from the Firefox mobile start page to get to my desktop's bookmarks toolbar.
If u log into firefox with an accounts by default it syncs so u can see all tabs open on all instances ur logged into. U can also send a tab to a device if u want the tab to open directly.
And there is always bookmarks which are also synced.