I believe these issues will solve over time by moore's law. By the time Web3 will be mainstream viable we will all be able to run nodes on our mobile phones.
Phones have batteries and maintain the decent battery life they have with aggressive sleep, control of background processes, etc.
Ethereum does a tiny number of transactions and I'm not sure Moore's law will keep up with any scale (see Solana and Polygon) as it applies to mobile devices. Then you still have the power and cell connectivity issues.
No one is going to want to wait for their local node on mobile to take a half hour (or more) to sync after it's been disconnected/idle/etc for a few hours/days to make a transaction that should take seconds.
