They are really two different kinds of animal. All the advantages you listed do exist, but they come at a price.
Yes, in principle, you can camp in a popup in all seasons. But if you come from a Class A, you will need to compromise on many things.
Most popups are smaller than most hardwall campers. Many have no or limited bathroom/shower facilities. I am not aware of a popup camper with a dry bath. Outfitter and Hallmark offer some level of foldable bathroom compartments, most others have curtains at best. None of that is good or bad, you just need to be comfortable with it.
Interior space is quite limited. Keep that in mind for rainy/bad weather days. No slideouts, either, for additional space. Storage space is very limited, too. More so than even in a hardwall TC.
Setting up camp and getting ready to leave always involves raising/ lowering the roof. No stealth camping either, as most popups can not be used with the roof down. Some campers require you to lift the roof to use the toilet.
The fabric does not insulate very well against heat or cold, but that can be handled with more heating or AC. You just need more energy (solar, batteries, propane). The sound isolation is also poor, and there is nothing you can do about that.
I have had both, an Outfitter Apex 8 LB popup which is among the most luxurious popup campers out there, as well as our current hardwall Northstar Arrow and a Lance 915. Both would be on the smaller side for hardwall campers - but they were still much more spacey than the Outfitter.
Also heavier and more cumbersome. The popup was very nimble, our rig handled like a sportscar. In the right weather, where you spend most of the day outside and just need a place to sleep, dress, store and prepare food, a popup is a great solution. There is nothing quite like that airy tent-like space. On cold, wet, rainy days ... less so. It is warm and dry all right, but not a great place to spend a lot of time.
Look at as many campers as you can, and try to imagine a typical camping day in your own camping style. There is no one size fits all solution out there...
We went back to a hardside for a number of reasons. One was the local climate here in central europe with many cool, chilly, rainy periods.