Even if there is no option for 100 year registration, 10 years is pretty common[0]. Google deactivates an account and deletes all data after 2 years of inactivity[1]. So even if someone stops using the domain, all data would be deleted after 2 years, emails sent to it would bounce for ~8 years, and only then could someone take ownership of the domain. Even if you're using another paid service, your payments would fail, and your account would also be deleted before your domain expires.
0: https://www.icann.org/resources/pages/renew-domain-name-2018...
1: https://support.google.com/accounts/answer/12418290