Technology like Algorand State Proofs are going to enable a kind of “compression” of blockchain’s verification, so that even with years of ledger’s growth there will be a way to keep the catchup process efficient and decentralized without trading it for network’s health.
This being said the point related to “transactions storage space” and the “ledger history inspection” is something different and realistically sounds like not a high priority bottleneck/blocker right now. There is a plenty of margin for the current storage solutions.
In my personal view, fast-forwarding the topic, this should be addressed on the ecosystem growth level, meaning that the solutions have to be shaped by the evolution of the network itself both in terms of infrastructure and incentives to ensure data persistency and availability.