Surely there are tradeoffs in having to rotate the certs that often, right? Notably, considerable load on their infrastructure. I get that urging people to automate their renewals makes sense (though I've also heard people unironically saying: "I want it to be a manual process, so I know how it works instead of relying on some black box"), but it seems that shorter and shorter cert lifetimes might put more strain on a service that nigh everyone seems to just be using for free.

Edit: at least there are a lot of prominent companies here https://letsencrypt.org/sponsors/