Config management took me many years to adopt, containers took me about 6 years to warm up to. But LE was something I jumped on immediately. I had worked in web hosting for 10 years already when it came out so I remember faxing your driver's license in order to validate a TLS cert. It just felt like such a scam for so long that these CAs were over charging for something that is just a key signing.
But I guess automation and standards had to catch up in order for LE to securely setup their CA.