Better CPU and more RAM i guess is simply a matter of speed. With my slow 2ish mbps link that didn't made much difference anyway.
Most Of Bitcoin Node Operation Is Reading(When Verifying Block), Not Writing, Therefore Node Activity Wouldn't Significantly Affect Your Storage Lifetime
However, If You Running A Node With Low RAM(Smartphone/Raspberry Pi/Potato PC), Write Cycle Will Increase, Therefore Shortening Your Strorage Lifetime.
Plenty Of Smartphone Today Have 6-8 GB RAM
The larger you make the dbcache, the fewer disk writes are needed.
#RAMMatters
Smartphone Will Be A Viable Device For Running Node In The Future
Perhaps when the node is in sync, but not while crawling the blockchain, and specially with prune. My HD activity wasn't trivial during the months it took my full indexed node to sync. Of course if you do that in ram (say, using a ram disk) it would lower most of the impact.
Given the specs of current smartphones (going beyond raspis) i have no doubt they can do it. On mine i used 4gb for dbcache (it has 8gb ram).
I'm not saying its not possible, just that you may end lowering your SSD lifetime prematurely by not paying attention, just like letting a swap file there when you default install an os into a SSD without paying attention.