As with everything there are usually different ways to carry out transfers. Here is one explanation of a scenario:
The loader has access to bank accounts or bank account info (usually online logins, or logs where they can see an active balance bought from a private seller or trusted online shop).
The cashier has access to bank accounts that are ready to load (opened with someone else's info in a fake ID, use own info, they know someone else they can trust, etc).
The loaders job is to send an ACH/Wire, etc from their logs to the drop the cashier has given the info for. The cashiers job is to quickly empty out the funds from the bank account that is loaded and send a portion of the money back, usually in BTC, to the loader.
Loaders can also obtain loans and use your account as a drop for those to cover another example.
The reason why a loader might not do their own drops could be several:
- The loader lives in a country other than the country they need the bank drop in
- The loader only focuses on loading (stay in your own lane)
- The loader does not like the risks involved in in person transactions
Hope this helps!