Altcoins have the benefit of experience. Bitcoin was the first and therefore issues that have arisen, such as ASICs, werent thought of. Altcoins, on the other hand, can see where Bitcoin is going wrong and change their coin to prevent that from happening
Altcoins are usually used less than Bitcoin so the transactions should be much faster with it.
Bitcoin has been having improvements over time with segwit and lightning network to start. Though i agree that with the bulk of btc uses, it takes less time and is cheaper to transact with alts. Remember last year whem btc charges were off the roofs?