The FDIC exists to keep banks afloat, because they're untrustworthy on their own.
For people, credit union accounts are federally insured just like bank accounts are, but credit unions are typically much more resilient than banks given the additional restrictions on how much leverage they can engage in. They close less often than banks, and also seem to be more likely to merge than close[1], contrary to your claim.
You're welcome to keep banking elsewhere, but it's all credit unions for me and my extended family.
0. https://thefinancialbrand.com/news/bank-culture/tarp-on-cred...
1. https://www.bankrate.com/banking/credit-unions/list-of-faile...
(your linked sources are horrible sources just in case you were not aware: both are paid media fronts designed to drive revenue through clicks, not reliable sources)
The main difference in my view is struggling commercial banks get absorbed, where as struggling credit unions close.
I am not sure which one is better, but I am wary of all the calls to go all in on credit unions. They've been available for almost a century now. They have a noble goal in that they've always tried to serve those in need, but I am not sure they are the solution.