Can a top level domain provider close their business? [duplicate]

If I buy one of those weird top level domains, like, or, etc, I understand that there is a private company owning each of them, which save the records and redirect using their own servers. (obligated to ICANN)

Question is, if this company closed, or go out of business, or just decide they don’t want to provide service anymore, what happens to all the websites with this extension?

In other words, is it safe to buy one of those top level domains? also, can it reduce speed if they don’t operate well enough?