GP's point is those things used to be a standard part of the service. They were done away in the name of convenience. Then later brought back for a fee.

Another example: self-service gas pumps.

And if you use self checkout you’re avoiding waiting in a longer line for a cashier.

Only in the beginning, when self checkout stations are being introduced and most of the customers go to cashiers, out of habit.

Thing is: even a person that does self-checkout quite often is still much slower than a cashier, who has 100x more practice. Also, when anything goes wrong with self-checkout you typically need to wait for someone to get to you and fix the issue - cashiers typically are able to fix their errors themselves.

So, in the end the lines will be longer, because of less skilled people doing the work.

Since self checkouts are cheaper to operate and take less space, it's compensated by there being more of them. Our supermarket replaced 2 checkout lanes with 6 self-checkouts in the same space with half the staff.

Then go to a cashier. If your store doesn’t have any, go to a different store that does.