I play Solasta exclusively on the Deck (as it's my only PC now), but almost ALL that time is docked.
The tiny text is a deal-breaker for my 40s eyes, re: playing it handheld. I'm working on a magnification screen rig at the moment (awaiting the parts) to address the issue in general, but just by default, on an 800p 7-inch screen, it's just too small.
I'm hoping that developers work on having clean and scalable fonts and UIs, as a growing percentage of PC gamers are going to be portable.
It can be done right. For example, I bought Inscryption on the last steam sale and played through almost all of it handheld, and every font in that game is either large as a percentage of screen real estate, or it's very, very clean and easy to read when smaller. That was a great experience on the small screen.