So true. Even on hosting that fully supports let's encrypt thru an web based admin like cpanel or directadmin, the process can be confusing and error prone.
If we're purely talking about Let's Encrypt, it's not straightforward to set up on Azure either.
It's easy to set up a standard cert through Azure, but if you want to use Let's Encrypt there's a whole dance you have to go through to get there, and for many people it's not worth the time and they'll happily pay a bit of money to make it a few-clicks thing.
When I looked at doing it, I'd have to bump up my hosting plan for my vanity blog to somewhere in the neighborhood of $100/month to apply an SSL cert for my custom domain, which is just stupid for a site that gets a couple thousand visits a month and maybe earns me $5 in referral fees.
It looks like you have to go up to at least a B1 app service, which at $50/month doesn't make a lot of sense for me, unless I can figure how to get my MSDN credits associated with that Azure subscription instead of one of the other two accounts I don't use, but that's a whole other can of worms...