Anatomy is a really easy mistake for any person to see, regardless of their experience in art. It's probably the easiest mistake for any random person to not only spot but to know what they are seeing - mistakes in perspective may take a minute to figure out, and shitty color and composition are definitely not going to occur to the average person immediately.
But by god, people who can't draw stick figures will know that your anatomy is cocked up.
And some of them will even want a goddamn gold star for noticing.
That doesn't mean you gotta fix it or do it well, but if it's a mistake even a beginner thinks they know how to fix, you probably should try to learn what you're doing so that people stop being distracted by your mistakes there. That said, if you care if your mistakes distract people you should probably learn what you're doing in a lot of different areas. But anatomy actually has very little to do with communication. Compared to, say, colour theory? Anatomy isn't even on that goddamn level. But it's immediately obvious, which makes it annoying.
It's a bit like a spelling mistake - a third grader doesn't consciously know how to care how you express your ideas, but if you misspell one word they'll spend so much time calling you on it that you'll never get them to pay attention and read your damn writing.
But in my experience, there's not really such a thing as "a lot of" anatomy knowledge the way most people think of it. The average artist on Gaia who thinks they know a bit of anatomy usually knows jack. At the point where you stop making stupid mistakes is not the point where you have mastered anatomy - it's honestly the first point that really matters, not the end goal. That's the point where you can actually start thinking consciously about what you want to do with it now.