And those people should avoid scammy apps that require their bank credentials.

What should they do instead?

Not use those services. I don’t think there’s any essential digital services that require bank access.

The closest is many Venmo/PayPal/cash app but there’s a way to use without giving login access. Instead it just uses the account and routing numbers to make ach transactions on my account.

This is still risky but still much safer, I think. ACH can be reversed. A login with my bank can do all sorts of stuff that my bank holds me liable.