Well, yes, it's something you are technically renting. There has to be a balance between cost and convenience. If there was a lifetime fee to own it, think of all the domains that would be already bought up - there'd be barely any left. However, in almost every case, there is nothing that will get your domain taken from you, unless you fail to pay or break the domain registrar's TOS (copyright infringement, etc). Far higher bar than Google's AI deeming you bad.
And regarding failed payments: My registrar at least emails me 30 days in advance, will email in case of failure, and will not put the domain up for sale until after a grace period (IIRC at least a week), during which they will repeatedly attempt to contact you.
Also, even if you can't own it: that's true of self-hosting also and doesn't apply to just purchasing hosting
