In my earlier days I don’t think any FF place knew what a microwave was. So sad but yet so predictable. [:(]
I think that there are four things going on:
1. Drive-throughs put pressure on to speed things up.
2. The menus got so big that it made it difficult to have enough volume per hour of any individual item to be able to deliver freshly-cooked FF.
3. Downward price pressure, i.e. "dollar" menus.
4. Customers put up with it.