I've been studying the bitcoin soft forks like segwit and i dont understand why we needed to add vBytes.
vBytes are added to accompany the change of structure in a segwit transaction. Segwit transactions are counted in virtual bytes.
From my understanding segwit leaves a blink section in the transaction where the scriptsig was in order to keep backwards compatibility. Which would cause the new segwit transactions to be more bytes than the P2PKH so to make users use the new segwit transaction type they made vBytes?
Backward compatibility is ensured by an additional information specifically for older nodes to make them still able to process both segwit and nonsegwit transactions together. This definitely adds more size but still allows for greater efficiency.