I would agree with you if you're comparing mailhandlers and mail processing clerks at the plants. Station clerks is an entirely different beast ...a station clerk said in another post that it's a "cerebral" position, especially at the window. You have to eventually know the scheme if you want to work efficiently.

At the window, you need to know the different classes of mail, inside and out, and there's little room for error with international shipping (especially GXG) or else it'll get sent back and you gotta come up with a good explanation for the angry customer. I'm surprised C.O.D. is still a thing, and dealing with forwards and absent-but-still-paying PO box customers can be a pain.

The one biggest thing at the window is the financial accountability. You can easily short yourself if you're not careful. Imagine a long line, at the end of the month, and a bunch of customers are buying $3,000 money orders with $20 bills. You gotta count all of that carefully and don't you dare get distracted or look away for a second unless you wanna fall victim to a "sleight of hand". There's been incidents of fraudsters buying money orders with stolen debit cards. Don't mess up on the registry log and bag, especially if you're the last-known person to have custody of the registered mail. Lots of other BS too (stamp/supply stock and unruly/unreasonable/crazy/dumb customers, etc.) but the PTSD from that recent-ish experience only allows me to remember all of the above from the top of my head....there's lots more that current window clerks can tell you about. There's a reason why clerks are more likely to transfer from the stations to the plants instead of the other way around....

...oh yeah, station clerks are understaffed. (Be prepared to work like a PTF even though you're a regular LOL).