Because shopify cannot instantaneously be all things to all situations.
There is an api to make custom apps the business owns.
If some feature “X” is business critical but yet at the same time it cannot be justified to invest in in custom processes for that critical need … that’s in indication of priority issues.
Shopify is not the only ecommerce software, shop around when it comes to important features.
for some reason they disable it when you are delivering your orders locally
Ask support specifically why that has to be like that.
Then document it and make a feature request boilerplate.
Internalize that there are tons of “must have” features merchants want, but very few ever bother to do the actual homework and legwork let alone get major traction in a single forum.
And even when there is some traction it’s only a couple hundred merchants insisting their need should be the priority on a platform that has to serve MILLIONS and almost all resent and rage at that hard fact being pointed out instead of using it as a metric of effort still required.
Don’t be another blip, look at historical discussion of features like the duplicate customer merge, combining discounts, shipping packages etc etc etc and how they either continue to fail or did end up getting added.