I think your sibling post is similar in sentiment and it comes down to transparency. In the "patches-to-a-list" model, there's no running status page or record of exactly what patches were rejected or ignored, and by whom. Anyone wanting that information would have to go to a lot of work parsing, searching, and analyzing the mailing list.

With Gerrit or pull requests, reviewers are clearly assigned and patch states are managed in a centralized dashboard. This makes it a lot easier for external stakeholders (managers, other development staff, etc.) to gain insight into how a team's working and whether or not they're being accepting or effective. And that's why, to me, these kinds of toxic maintainers seem to suffer an extinction event when moved to a more transparent system. The maintainers are the same, but their tool - quietly rejecting patches with little accountability - is taken away from them.

You can allow multiple person to accept a pull request. So you don't have "a" maintainer but some.