Running a full #bitcoin node on your phone will be relatively reasonable in the new few years.

The biggest hurdle today is storage for the history of the blockchain, that's currently just north of 500 GB.

The second biggest hurdle is battery usage.

The storage won't be a problem in a few years. The top Samsung and Apple phones have 1 TB of storage. That'll become the new standard with top tier having 2 TB. Phone storage increases as the price of the tech decreases.

Battery also won't be a concern soon. In a few years the top phones will have huge battery capacity. Even more importantly, they'll charge in just a few minutes.

4G and 5G are plenty, plenty fast in terms of internet speed. At least in the US, unlimited data is readily available and the standard on most plans.

A bitcoin node simply being an app on your phone will take the decentralized ledger to a whole new level.