I can say as a Pixel 9 Pro Fold owner, I have used it. And never once have I really needed a full keyboard and mouse for what I'd even think of using my phone for.

I only use it for some mobile gaming, and websites that do very poorly on mobile despite that being the only online device for so many people nowadays.

Having actually use one as a daily driver for over a year,... it's not worth it. It's not worth the additional weight and bulk, carrying it around all the time for the handful of times I do use it. And without a significant battery increase to justify despite being literally twice as thick as a normal phone.