You'd probably see similar delays in banking if all banks had to record all their transactions in a central database. It's simply not a scalable system.

But Bitcoin only has a few hundred thousand transactions every day. What database can't handle that small number of transactions?

Bitcoin is not, in my opinion, a system for transactions. It's essentially a store of value - that's it. If you want quick transactions, you won't do it faster with decentralized than with centralized systems. Decentralized is slower by construction

bitcoin is a byzantine fault tolerant distributed database, it's performance characteristics are different.