I think this is part of a downside of rebase-centric workflows, since it encourages making multiple branches with identical changes, but no shared history. At some point I want to read more pros/cons on different workflows. My current thinking is that rebase-only sacrifices far too much on the altar of a clean-but-inaccurate commit history, but I don't yet know enough to say for certain.
https://www.git-scm.com/book/en/v2/Git-Tools-Rerere
If you have a lot of long-lived branches that don't merge and get deleted you have a whole different world of pain from normal git usage, and need some resources designed as SCM experts to manage this stuff. But really short lived branches that deliver net steps forward are the way to live.
I hate branches because it breaks git-bisect. Linux kernel history has lived without it, so I'm guessing the "our code is so complex we need it" is a false idea.
Also, the actual history of what main/master points to is linear. If the bit-post merge are identical, it doesn't matter if they were rebased or not except having 2 ancestors for HEAD is a lie.
Can you explain what you mean by git merge breaking bisect? I've never run into that problem at all. And sure, it might bounce between the branches as you bisect, it still identifies the commit that introduced a bug. The only issue is if one of the commits on the branch fails to compile/test, which is poor commit hygiene, but can be excluded from the bisect.
I still need to do more research, but I think I'd lean toward having a merge workflow, but with no fast-forward commits. That leaves a clean history on main with --first-parent, but still leaves the details available in the branches as needed.
Those guys are still sending commits (patches) to each other by mail, I think they willingly live in such a special and weird bubble that it just can't be compared to any "real life industry project".
We've recently started to enforce linear history on our main branches at work, because it makes analyzing broken builds such a breeze. The mantra is "Insertion is hard, analyzing/understanding is easy" (for a merge-based history, it's pretty much the other way around), and so far it's quite the success.
It did take quite a bit of effort though to get everyone up to speed, and it still requires the occasional help to clean up the commit history of some merge request, but it was well-worth the trouble so far.