Transactions rarely cost more than a few dollars. We need better ways to trustlessly share UTXOs so that they can cost $1000+ because they probably will at some point.
The ~4mb limit has nothing to do with the cost of a harddrive.
It already costs a couple hundred dollars to buy the hardware needed to run a node. Storage & computational demands have grown & will continue to do so.
Lopp has written about past efforts to sync an ETH node from zero, which took weeks when everything went right & it repeatedly failed. Do you understand how fragile the network becomes if downloading & verifying everything takes that long & any significant number of nodes gets wiped out?
If only Google & Visa can run nodes then we have just recreated the Fed banks. They can change the rules & the supply however they see fit.
The cost of running a node gets exponentially larger as the number of nodes shrinks. Everyone who uses bitcoin has to connect to a node, what happens when the number of leechers massively outweighs the number of seeders? What does that do to the cost of seeding info?