What people, groups and businesses who were kicked off Facebook did wrong?
It seems pretty amazing to me that most entities are comfortable with the idea to put their intellectual property onto the platform of their competitor or adversary.
When Parler went down I could not help myself but laugh - what made them think that a "political adversary" is going to continue hosting them? This is in the light of the fact that they could have hosted in Canada, Mexico - even in Africa or in Japan - and slowly could have moved their platform to their own data center the same way Gab learned to do it.
The cost of a small Virtual Private Server (VPS) with backup is about 10 USD / month. You may put this onto an isolated instance or onto a cloud that may grow to any (practical size), on-demand. Of course you need to recruit the talent who know how to do all this and more - for example how to move all YOUR PROPERTY from one domain, service provider, technology platform to another without you noticing much delay or being hit in the pocket.
The cost of the technology is mostly in the support staff - you MAY start with 2 CPUs and 8GB RAM single VPS, on the budget - but you cannot do the same with your support staff. They draw the six figures from day one.
So to really "learn" to use Linux you need more than just understanding the bash shell, or using a CAD software. The real value is learning to purpose it and support it for OTHER PEOPLE. I started at the same spot years ago where Gab was, Parlor is today, and anyone may end up if they ignore the fact that we all must build our communication and social platforms - we no longer should trust anyone to provide for us.