and venting in general imo. my point is: imo, through thinking about your problems, you get to realize what exactly makes you feel bad and thus will be able to plan out actions intended to remove the cause of those feelings of bad. and when the venting is public, some others get to see that they're not alone in their issues, which enables them to contact you in order to team up to resolve the problem together, share tips, or at least provide an opportunity for further communication; one can befriend people too this way, for talking about stuff that's outside the vent problem
so, venting is needed for teaming up with people
h*mans will say bad stuff about you for venting, but that's because they prolly wanna be higher in the social hierarchy
and i do believe that if you do venting when the same issue was already expressed by you before in an older vent, it will not be a good spending of time. maybe in such situation you can think of any advice to give to the readers, and write that instead. imo even little solutions to make the harm from the problem not that big are already very good things to do