I’m noticing that a lot of questions aren’t marked as solved when they really could be. Right now, the configuration requires trust level 4 for anyone but the OP to mark a reply as the solution. I’d like to propose moving that down to level 3. That still requires quite a lot of commitment to the site (visiting 50% of all days, reading a lot of posts, giving a lot of likes), so I think people who earn this level can probably use the check-mark responsibly.
You mean trust level 4 is required to mark someone else topic as solved. The one that asked the question is able to mark their own topic as solved even if they are at trust level 0. Right?