It depends. If you know you have issues, aren't dealing with or handling them to your satisfaction and want help? Absolutely. Therapy, treatment and proper medication generally require an official diagnosis, not to mention potentially being cheaper when you don't have to pay for all of it yourself. If you know you have issues, but have also developed effective coping mechanisms on your own and negative effects on your life are overall rare, I think it's fine to keep going undiagnosed, as long as you're mindful of your problems and how they affect the people around you.

Couple examples from my own life. I knew I was depressed. My friends knew I was depressed. I thought I was handling it okay, but I really wasn't. So I got a diagnosis, so I could get medication and therapy, that allowed me to build coping mechanisms to hold it at bay. I'm also fairly sure I'm somewhere on the autism spectrum. Where, exactly, doesn't matter, since I can manage life and socializing just fine, I simply have to think twice about what I say. And when I'm not sure of myself, I have trusted friends to go to for a second opinion. And then there's the undiagnosed face blindness. A diagnosis won't help at all, since there's to treatment or medication. I had built workarounds without knowing I was doing it, years before I found out face blindness was even a thing

In the end, if you're unsure, you can't go wrong with getting a diagnosis. If nothing else, it will at least tell you more about yourself and serve as a guideline for how you manage your issues.