Usability is a little better on the PoS chain. Blocks come out every 12 seconds, instead of randomly with just an average time of 13 seconds.

The PoS chain takes less than a minute to converge to a state where it's very unlikely for your transaction to revert, and in 12 minutes your transaction is finalized, meaning it can't revert without destroying a large percentage of staked ETH.

PoS ETH will have the researcher and dev community building on top of it for another decade or so. There's a long list of further improvements in the roadmap, including major increases in scalability.

Most of the ecosystem is moving to PoS. The popular rollups will be connected to the PoS chain, not to PoW. Major stablecoins backed by off-chain assets have already said they'll be backing the PoS chain, not PoW. Etc.

You're right, if users disregard the difference in energy consumption there is little reason for them to choose the PoS chain over the PoW one. For devs and businesses the PoS one seems to matter though, I think it is likely the activity and innovation will be there in the end.

Also a user would have to make an effort to keep using the PoW one AFAIK.