There is a natural tendency to try reinvent something when you don’t understand it enough to be comfortable with it. Then that new thing lacks the maturity and scrutiny that the old thing went through to survive the test of time.
While this is something that does happen, there's also a tendency for people in the industry to dismiss new things without actually looking into the pros and cons.
Doesn't it give you pause that many very experienced Frontend & CSS developers see objective advantages in Tailwinds utility class approach? Of course there are also objective disadvantages, don't get me wrong. But that means that these tools should be used whenever their advantages can shine and their disadvantages don't cause issues.
Any developer that can't clearly name the issues with regular CSS that Tailwind attempts to solve either hasn't been developing long enough to encounter these issues, or hasn't actually tried to understand what Tailwind is.