> Letsencrypt's users are almost all in the personal/hobbyist space

That may have been true in the early days of Let's encrypt. But today, if you're using any of a number of newer hosting options (Netlify, Vercel, Fly.io, etc.) you're probably using a let's encrypt certificate.

Older/more staid companies will mostly still be using certs from Digisign et al., but there's little reason for new companies to pay for that.