This has always bothered me a bit, the way it used to work was that the payout from delivering a crate was based on your level of charisma. I'm not 100% sure if that's still the case but I feel like it is.
I always thought that crates should be based on your strength in addition to your charisma. If you're of higher strength, a stat check / weight check can be done and give you a different sized crate to deliver and each size of crate has a different value associated with it. e.g, Small (100), Medium (300), Large (500) and this could be scaled to match the current average payout from a day's work but cut down the amount of time spent delivering many small packages and get people back out there to the RP quicker.
Charisma could still be used to add a bonus "tip" to the top of a delivery and that'd be a sensible application of the stat in this case.
I just can't wrap my head around a warehouse caring how pretty or charismatic you are when all they want you to do is take package from point A to point B.
This way things make some kind of sense and for people who really spec out for strength and want to be seen doing things that only a strong person could be doing.
And I'm not trying to make crates more lucrative to do here either, I'm perfectly fine with the current payouts.