I can understand this can cause pain for existing deployments, but I don't see any reason not to use something like Let's Encrypt to issue 90-day certificates f

I can understand this can cause pain for existing deployments, but I don't see any reason not to use something like Let's Encrypt to issue 90-day certificates for new services/deployments. With certbot, renewals are automatic and with something like Caddy, the certificates can be managed across load balancers. I'm only talking about the web service here and not IoT or any use case that makes this sort of frequent renewals difficult.