I want to second this. With only a little effort initially, I've been able to have fully automated SSL-by-default for all of my "backyard hosting" customers, at no extra cost for them or for me. You folks are wonderful.
I'm adding my voice: Let's Encrypt and Certbot have made my life much easier. We manage somewhere around 100 websites where I work, and we were probably no more than 4 out 5 to monitor certificates, and renew them actively. It's a million times easier now.
Kindly convey my thanks too. You're the actual guys who are making web secure. Browsers just say, your site is not secure, but that doesnt help at all. Having cheap and easy way to solve problem, can only make it work.
Interestingly, many CAs are charging lot for certs. And lot of them don't know how to validate user's info. Many business guys just burn cash on certs told by CA's support team for 'security'.
I would also like to give thanks! I just use in on my home-hosted site for personal use, but it was such a breeze to set up. I could have used a self-generated cert but I feel this is much safer, and saves me from having to install the cert on every device.