1.- The type of consensus to decide which miner will win to carry out the transaction by its nature is slow depending on the potential that it needs at the computational level (solve the mathematical puzzle that is this).
2.- The verification to accept a transaction is another reason (merkle tree) how each transaction is classified to prevent double expenses.
You're just talking about the block intervals, no one decides which miners win. Very simply, whoever can extend the chain by providing a valid PoW can lengthen the chain.
Transaction validations are very fast, in the neighbourhood of milliseconds. You're just removing data from the UTXO set and adding new ones, validating the signature, etc. Any modern computer or devices can handle that quite quickly.
Bitcoin definitely needs to be repaired in the future and newer algorithms used for optimization. The reason why Bitcoin is slower and more expensive than in the last 5 years is also clear. Thousands of small and large transactions are encountered every day and they have to adapt the previous network with new algorithms.
Let's give Bitcoin a chance, we're still talking to the King of Currencies.
Bitcoin will always have a 10 minutes block interval. You can scale Bitcoin with certain optimization but changing the block interval can net a faster confirmation if that is all that you care about. Rather than it being slower, it is just more expensive. There are efforts made to optimize each transaction but there is a point the optimizations would hit a wall.