hi! here's a semi-serious post about criticism that will probably be helpful for those critical people out there.
criticism is, most of the time, a good thing that people do to help others improve. however, here are some times where it can get out of hand, and here are some times where you SHOULDN'T criticize people:

1. the person is obviously better than you /lh
for example, you're playing volleyball with someone that is obviously more talented at it than you are. but, ignoring that fact, you criticize them, saying "no, no, not like that!" "NO, you're supposed to hit it with your platform!" "NO! SET IT! don't hit it!" this is really disrespectful and honestly triggering. to make an extreme comparison, it's like me telling lilypichu "what the heck your singing sucks and you are off-pitch". or a 5th grader telling Michael Jordan, "you need to do a layup instead of a dunk; try to do better." i think you get what i mean.

2. the person does not ask for criticism.
this is an important part. I've seen SO many people on AoPS, Instagram, discord... everywhere, that give criticism when people don't ask for it. if the person says, "please criticize", go ahead. but you have to understand that some people do not appreciate criticism as much as you; some may even be sensitive to it (like me). so, accept differences, be kind, and don't criticize people when they don't seek criticism. if you work hard on something and post it just for people to say, "maybe you could colour that part and shade that part and your lineart is kind of messy" you're going to be upset. most people are, at least.

3. the person is proud of their work/skills/etc
if someone posts their art, for example, saying "omg i worked so hard on this and I'm so happy with it!" then the noble thing is to probably say "good job" instead of criticizing. it can be upsetting (i know this from firsthand experience) when people criticize something you worked so hard on and thought was near-perfect. if someone is obviously proud, or maybe hinting that they are proud, just say "nice job!" it's going to save both you and the other person a ton of energy and time. (exceptions: teachers/student assistants, maybe just say something like: "this is outstanding! but, maybe work on [this] next time."

so, i hope you guys will read this and maybe think first before criticizing again.
of course, criticism is an important part of our lives, but we must be careful that we are giving it to the right person at the right time. it's not too late to change yourself and your thoughts, remember that!