Ex party girl here from an era before most of you here. Gone through all the same things of becoming invisible to males after crossing a certain age and having no suitors when I wanted to quit the party scene. Same grating CNY questions, same getting wedding invites and being jiemei over and over again until I was the only unmarried one left.
Had all the same rationalisations that you are having now, blamed everyone for such an unfair system, tried to convince myself I was happy and complete unlike all my friends shackled to marriage and kids. Yes I was also one of those you-don't-deserve-me-if-ya-can't-handle-me-at-my-worst girls. Guilty as charged.
It starts slowly at first and maybe denial has a part to play, but one day you will notice how your FWBs have moved on and ended up in LTRs, thereafter getting happily married (yes it's unfair but that's how it is). ONSes will dry up because the clubbing men are all flocking to younger girls who look like what you used to. Your clubbing pals who weren't as havoc wreaking start dropping out one by one as they settle down and you will feel like the person who couldn't secure a chair when the music stopped playing. The tattoos you got then to show how hip and sexy you were will start to look silly years later and you will spend more time convincing yourself how it was a good idea instead of admiring them.
You will still attempt to get into LTRs but you mainly only know how to hook up with uncommitted men who just string you along until one day you get "the talk" about how things aren't working out. Even that devoted nice guy you friendzoned back then and now consider reconnecting with out of desperation is happy attached and sends you his wedding invite. You bite your lip with every failure experienced.
All you have is a job you no longer like. No energy. Returning to an empty house late after work. Lots of nights thinking about what could have been if you lived more for the long term in your 20s.
Experienced all that. Many girls in my position can go on deluding themselves about how they are complete without having a significant other but I guess that is just not me. Granted there may be one or two who are really happy that way but the thing nobody wants to talk about is how many of us are not because no one wants to hear about that.
In the end life is about choices and you can't have it all. I am not saying all this so you will pity me, I have long accepted that a loving husband and kids are something I will never have; to think I used to hate these ideas when I was younger. I can only blame myself for acting overly self-entitled and thinking the world owed me no matter what choices I made. I am tired of blaming others.
All I want to say to younger girls not so far down the path I took is that one day the party will end and the hook ups will dry up. Soon enough everything will ring empty. Live for things that matter. Be wise.