I found when I got an iPad (I never had a laptop at home), that I stopped using my phone much but when I do use it, I still need all the main features of a smartphone, like a decent camera, apps to manage everything (maps, public transport tickets, apps to order food/drinks etc), sadly everything is in a very app world these days.
I wish there would be more effort put into making more basic smartphones, less running full blown OS and just have a few basic functions, like a decent camera, internet access, messaging and maps, but because they are mini computers they are bloated as hell.
I tried doing that a couple years ago. The problem with dumb phones (or at least the problem when I researched this several years ago) is that it’s a niche market with high enough demand that all of the products are low-effort, low quality and exorbitantly priced for what you get.
I won't argue low effort, but I just went to my carrier's site (Verizon), and I can get a "basic" flip phone for $80 unsubsidized. The high end of the range, a ruggedized Kyocera, was $240. I don't think this is unreasonable for a range of devices that have much lower market desire than they did 15 years ago. At $80, I'd call that a disposable travel phone.