I'm not sure why this announcement has generated so much irritation in the comments-- Cloudflare has been transitioning from "DDoS protection" to "AWS competitor" for many years now, and this is just their alternative to AWS SES. It's an email sender that you can access through an API, or directly through Workers. For those who haven't been keeping up over the years, Workers is their product for running code on Cloud…
I guess they got that reputation years ago when the founders (?) got into public spats about what they would and wouldn't host. AWS is more lawyers and committees and seems more anonymous, so people don't necessarily like it more but they do trust it to be what it looks like more.
Probably just a function of time and size.