Can confirm. I’m a bit older, but when I stopped using social media it was like my aquaintances forgot I existed. Sure, close friends would usually still invite me to social events, but even that tapered off after a while. When I’d call someone out for not inviting me, their response was always “but you never shiw up to anything”. It’s not like they don’t know that I’m not on Facebook. What, you think that when you don’t invite me that I’ll just magically know it’s happening? I’m finally getting some people to use Signal groups but that has been an uphill battle.
So long as, in the absence of rules, everyone is treated the same. Major social media platforms swing hard right, meaning that leftist positions will be marginalized regardless of the rules or absence thereof.