@CecilieRose
I think single life is so isolating as you get older. My relationship isn't the best at the moment but I feel like if I left, it would be even worse. In my mid thirties, almost all my friends are coupled up and so many social events are 'couples' things that you just don't get invited to if you're single. I was single for a while before I met my partner at 34 and it felt really good to suddenly have that 'default' person to do things with - go for a drink, weekend away, hiking in the countryside. I am a very independent person and have done loads on my own, including travelling the world and emigrating multiple times, but it's just so nice to have someone to do stuff with, and the older you get, the harder it is to find it in friends, because they're all busy with partners and families. I loved being single in my teens and early twenties and never felt like I was missing out but that's because there were so many opportunities to do stuff and meet people.
Possibly it'd be isolating for you if the relationship broke down (it all depends what else is going on or not in your life). Do you have a good family support network? A large, diverse friendship group?
It is sad that in society relationships are revered so much - and given far too much status symbol - I know I was married and I acutely recall the 'privilege' - and being a single and in particular childless woman - as some sort of social pariah.
It is nice having a 'default' person to go to but all relationships too a degree are fickle so what is now the default may not be the case in 5-10 years. I don't want to be reliant on one person alone as you never know what could go wrong.
The issue is the way society is structured and organised, and I'd much rather have a genuine, community with lots of people to choose from to do things with rather than having the one and only 'default' person. It is an utopian fantasy, I know, but I'm doing things differently (solo mother to be via sperm donor) so I am used to doing things the unconventional way. But, that's me.
Single people are shamed to an extent and the trope is to 'keep' looking/dating until you find a partner. As we've already pointed out on the thread, life is expensive as a singleton, I think this is one of the biggest societal 'punishment' (though I've not experienced not being invited to events because I'm single).
I don't think it's just in the 20s that you get to meet people (predominantly university?) and do stuff, this is still possible in your 30s/40s however it does take more effort.