Most businesses can treat their domain name as fail-safe. If you have a .com/.org/.net, pay well in advance, and aren't doing anything that's currently illegal in the US, you're not going to lose it unless there's a dramatic political shift that's earthshattering for ~everyone.
On the other hand, social media platforms arbitrarily locking you out is a daily occurrence for tens of thousands of innocent people per day. This isn't just a hypothetical risk, it actually does happen to people and businesses all the time. Even the most law-abiding business should not build their castle in a social media platform.