There are a lot of complaints around suggested edits that only change tags. Some reviewers automatically dismiss them as too minor. Indeed, too minor is the main complaint — not incorrect. The end result is that despite the issue coming up again and again, questions aren't getting the right tags as fast as they should.
Tags are important — they direct the question to its target audience. An edit that does nothing but put an appropriate main tag on a question (for example, the programming language or framework on Stack Overflow, the operating system on Super User, etc.) is an important one and needs to go through as soon as possible. It doesn't matter whether other things need to be fixed in the question: the first priority is to make sure that it reaches the right people.
While we can't hope to fix all the chronic problems with suggested edit reviews, there is a simple way to alleviate this problem.
Lower the reputation requirement for tag-only edits.
The reputation threshold for tag-only edits was at 500 on graduated sites for years. This was taken away for no good reason — in particular, not because incorrect tag edits were getting through. Bring it back.