I see many posts advocating the reduced transaction size in taproot, but many fail to note that they are assuming multisig transactions. For basic, non-multisig, single-signer transactions, segwit is still smaller (and cheaper) than taproot.
Taproot has smaller multisig transactions than multisig-segwit, and this is what most are referring to.
For a 1-in / 2-out transaction, P2WPKH is 9.6% cheaper than P2TR. But in a 1-in / 1-out the savings drops to 1.5%
Update: found a better TXN size estimator than mine, so I linked it