I guess the real question here is: Who is more likely to ban you, Google and co or your domain registar?
For most people, who are not doing anything shady/controversial with their domain and are using a .com or .net domain (which are price regulated by ICANN), are not using a shady registrar and will always have the cash on hand to renew as needed, the answer will be Google and co.
Its a good idea to set up auto-renew on a credit card, so you can be sure it will go through and you won't forget to renew it.
I pay for 10 years in advance, which you can do with com/net/org.
Not a bad idea, although i'd worry i'd forget to renew, may not remember something I set up a decade ago at the right time.
I guess another consideration is also, should something happen, what level of support will you get?
Most domain registrars will at least have some customer support.
But good luck getting support for a free gmail account.