Without the witness discount, you would have UTXO bloat.
Discussion
That can be mitigated by Cross-Input Signature Aggregation.
For taproot only?
Yeah it would require new output type segwitv2 and using Taproot/Schnorr.
So if we decrease or disable the discount, it wouldn't have such advantage.
But real financial transactions would have a benefit as you can easily consume outputs.
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