Cloudflare protects against DDOS but also various forms of malicious traffic (bots, low reputation IP users, etc) and often with a DDOS or similar attacks, it's better to have the site go down from time to time than for the attackers to hammer the servers behind cloudflare and waste mass amounts of resources.

i.e. it's the difference between "site goes down for a few hours every few months" and "an attacker slammed your site, and through in on-demand scaling or serverless component cloud fees blew your entire infrastructure budget for the year.

Doubly so when your service is part of a larger platform and attacks on your service risk harming your reputation for the larger platform.