There are tradeoffs to be made at any point in the cost level of phones; I've found mid-priced phones to be the best value for my own particular uses, with "value" phones being underpowered and having too small screens for my ham-hands, and with flagship phones offering diminishing returns in value.
Also, 'phone' is a funny word these days -- for most of us, the actually making calls is a small part of what it does. For actually just making calls, sure, most of us would do fine with sub-$40 dumbphone -- it would just be inconvenient to carry one on top of the the more heavily used device