imagine getting to see a 'unverified' balance within seconds of opening your node for the first time. via SPV methods(grab a rlatively fresh UTXO set from peers). and thus using a fresh UTXO set, then able to know you have imported the correct wallet by seeing aatleast a unverified balance and also then able to make transactions.. then the whole blockchain syncing becomes a background issue rather than a stare at the screen waiting issue
its like online gaming/phone apps these days. get to play with a small single level demo of a game whilst the whole game downloads in the background. people can the be instantly entertained and not be as concerned about waiting for the game to download, as that main download is treated as a background issue
Why not just use a lightweight client then? If you just want to send transactions and see your balance then you can just import that wallet in an SPV client. The assurance you get from verifying all TX's via your full node isn't meant to be an annoyance, we shouldn't be taking a full node and downgrading it to some kind of hybrid; there's a reason SPV exists.