In addition to the money changers (who exchanged local currency for Roman gold or silver), the dove sellers were also expelled. Doves were the cheapest sacrificial creature, and they were gouging poor widows.

The whole point is that the temple authorities were part of and profiting from what was happening. Jesus was dead with 10 days of this event.

There is a lot of depth here and it’s a genuinely fascinating story whether you ascribe to religious belief or not.