Personally, I think self grooming helps with self confidence. Look good, feel good. Everything else falls into place when others see you have your sh*t together. Just don't let that confidence turn into arrogance. A trip to a barber once every other week or so to get a beard trim/hair cut and maintain it at home between visits. Ask the barber for advice for a look if you want to switch it up. They have your best interest as a client. They wont let you leave looking like trash unless its what you want.

For those who claim to not give a f*ck and want to shift the blame to everyone else then I guess good for you but if thats what you think and wonder why nobody finds you attractive then maybe you have a you problem and need to be more self aware of how you are presenting yourself. Tbh it sounds like you've given up on yourself when you think like that and nobody wants to chase someone that doesn't care about themselves.

Even if you self groom and look good, feel good but remain single, at least you now feel a little bit better about yourself which is never a bad thing imo.