I found some reel son instagram of all places where people were messing around with restoring old PDA's and other kinds of older tech from the early 2000's. Vaporwave got popular and I think it caused more people to be interested in tech from that time.
I think there also may be a sorta "smartphone fatigue" that's building up as well. People tired of having their privacy invaded, people frustrated at the modern smartphone ecosystem, people who just wanna be able to unplug from the internet and be to theirselves. I can honestly see a small movement building of people ditching smartphones for these older devices that have the same productivity apps, but without the distractions or privacy risks of the modern smartphone ecosystem.
I don't know if you know the comic Ari Shaffir but awhile back he got rid of his smartphone and switched to a flip phone and then a lot of other people started doing it too for awhile.
And I think he still uses just a flip phone and he's like entirely removed from social media - or last I heard anyway. He still has a manager who does stuff for him.
LGR did an episode on an HP PDA he had in college, and it inspired me to run out to eBay and bought something I always wanted at the time but never sprung for: A Palm m100. The ecosystem for it is completely dead and it's almost unusable, but you know what? The seamless flexibility that the built-in productivity apps work together--the way you can put a note with a checklist in it in a reminder and it just works--My modern day Samsung has both Google and Samsung software, and neither one did it as well.
You say the ecosystem is dead. Technically yeah it is, but there's a fantastic archive of old PalmOS applications that's being really well taken care of. Mostly old programs from back in the day (most of which are cracked), but then you have dedicated fans making new apps, like that one dude who built a version of Wordle for PalmOS!
Best part is that it even has a version that can be easily accessed from Palm devices, stripped of its modern features to give you a basic interface that works on hardware not built for the modern internet.
I lusted after the top end Clies with the OLED screens. I had a T665C Clie, a Treo650, and countless pocket PC models including the HTC ultimate (Imate JasJar technically) and several others before android and the Iphone came around.