Only have one transaction type. Pay to public key hash.
1. Why not pay to compressed public key, without any hashing?
2. Why not restrict it to only valid public key coordinates, to have all existing UTXOs always "mathematically spendable"?
In case of hashes, it is possible, that some particular value could be simply unreachable, and then you won't know, if a given UTXO will ever be spent or not.
of course you are right. that would all be EVEN SIMPLER. and the simpler the better. as long as we agree not to worry about theoretical quantum computing attacks on published public keys. they're not a thing right now. but if was designing a brand new crypto system i think i might need to make it quantum resistant somehow.
You talk as if OP_RETURN, segwit and taproot bring no advantage. Should we remind you to few of these facts?
leave "memos" (aka OP_RETURN) to yellow sticky notes on your refrigerator. i wouldn't have it my crypto system.
Yes SegWit did solve the transaction malleability issue and improved signature verification time but i don't have an issue with those bug fixes. i don't think an entirely new address type was needed though. we need to keep things SIMPLE.
I don't find Taproot to be a compelling argument. or necessity.
but thanks for your insights.
1. OP_RETURN created mainly to reduce P2PKH abuse by encoding 20-byte of arbitrary data as public key hash. It means less UTXO which will never be used.
2. SegWit practically solve transaction malleability and quadratic sighash problem.
3. Taproot let you only reveal part of the script. It means slightly better privacy and less TX size.
if as vjudeu pointed out we used just P2PK instead of P2PKH, you can ensure that every utxo is spendable and not just some burn address. so i might agree to his idea...