The whole "Let's Encrypt should solve all your problems" attitude is arrogant and short-sighted.
1) In my experience the user experience even for technical admins is still flakey on at least some popular platforms. In other words, it's not as incredible as you think.
2) It's not available to a host that doesn't connect to the internet but does occasionally get connected to by a local browser (eg. IoT firewalled inside my LAN is one obvious such case; I'm sure there are others).
And most importantly:
3) You'd have to be insane or naive to accept an architecture that leaves you dependant on a single vendor (especially if you need that vendor more than they need you!).
1) In my experience the user experience even for technical admins is still flakey on at least some popular platforms. In other words, it's not as incredible as you think.
2) It's not available to a host that doesn't connect to the internet but does occasionally get connected to by a local browser (eg. IoT firewalled inside my LAN is one obvious such case; I'm sure there are others).
And most importantly:
3) You'd have to be insane or naive to accept an architecture that leaves you dependant on a single vendor (especially if you need that vendor more than they need you!).