Somehow it's really hard to find numbers, but AFAIK at least Telekom and 1&1 don't use CGNAT for home connections, which already rules out that 77% have it.

Questions like this suggest that 1&1 do: https://forum.openwrt.org/t/solved-dsl-over-ds-lite-with-isp...

I'm less sure about Telekom. For obvious reasons, it's hard to find info in English.