In my cases I has to solve same code conflicts multiple times during a rebase, so I just don’t try them when hit with conflicts.

Yeah if you have two branches, both with a bunch of commits which all modify the same areas of code, and reordering the commits doesn't help, I can see how it is easier to merge.

I fail to see the benefits of “clean” git history

Well, if the commit history is clean and mostly linear, it's much easier to read, understand and review. git blame will also be much nicer which is really important for debugging big codebases. Of course it's a tradeoff, as usual.