I've never had a cell phone that can match the latency of a 80s or 90s landline for local calls. Maybe the audio is as good, but that delay makes calls distinctly worse.
I did the same thing - replaced my laptop with a tablet for a trip. Lenovo P12. It I thought the windowing was great.
The whole experience would have been great, except for one thing which made it unusable for my purposes. Android has that clipboard editor popup that can't be disabled. When using Emacs within Termux, every time I hit ctrl-k, I got that damn popup which blocked a significant amount of the screen for ~10 seconds.