You could restart an entire Bitcoin network from a UTXO commitment. Running a full node to "validate all transactions" trustlessly is totally unnecessary.

As per the flair: This is my OPINION.

But I heartily invite contrary views.

Make your best argument for why home users should need to run a node that stores all blocks.

There's a great way to ensure that the entire history's block data remains economically decentralized. It's called Fountain Codes.

https://arxiv.org/pdf/1906.12140v1.pdf

If history is anything to go by, this will probably be widely adopted on Bitcoin Cash before you see something like it in Bitcoin Core (which frankly, will never need it because they don't plan to scale L1).

Apart from that, if you're only running a node because you want to help validate the network's consensus (i.e. "keep the system honest"), then you can also just run a pruned node today, with sufficient backlog of blocks (maybe 5% of history?). Bitcoin chains will never do massive deep-reorgs without there being a great consensus crisis (like there was during ETH/ETC split).

Bitcoin transactions are essentially immutable once they're buried a few blocks deep in the chain.

Chains that don't have as much hashrate as BTC yet, like BCH, can protect themselves against hostile deep reorg attacks, by considering blocks of a certain depth as no-longer-reorganizable. In practice this seems to work.

As long as you update your client software, you can validate current consensus on any such chains at very low cost - in a pruned way.

And in future, with UTXO commitments, you'll be able to sync them up in a jiffy too.

So there you go. My opinion is that decentralization is not at risk through on chain scaling. The tech to mitigate this all exists.

Change. My. Mind.