What kind of car do you have?
If you've got a smaller front wheel drive, you're likely to be limited to the smaller pop ups anyways so I wouldn't worry about "who's got what" if you don't intend to get a bigger car or truck.
If a pop up is all you need to be happy, then get a pop up.
You probably see fewer pop ups around because those owners tend not to be "long haul" campers.
Most pop ups end up on shorter weekend jaunts or off in a "non commercial" style camp site (IE: boondocking).
Bigger hard sided RV's tend to end up where they can have electrical/water/sewer hook ups.
We started out with an old popup ourselves. It was great to go from a tent to something with easy pack up and being off the ground. But that was just for a jaunt down the road on a weekend to get out or maybe a base camp when going fishing with the guys. Funny thing: everybody used to tent when we went fishing. I showed up with a popup first, then everyone started showing up with a popup. Seems tents were no longer "fun" when the next guy had a table, stove, fridge, and dry sleeping even in a downpour. I guess I ruined it for everyone.....
Then we started traveling longer. The limitations of a popup began to get on my nerves. Two weeks in a popup really shows what you miss in today's conveniences. I also got tired of cranking it up and down, the sound of flapping canvas/cables and everyone around us knowing exactly
what we were doing all
the time. So we got a decent sized hard side and things were good.
Then we started traveling further as well as longer. The limits of a smaller hardside started showing up as we were using it as a "base camp" to see things in the areas we went to (IE: yellowstone, etc) A bigger trailer enhanced our trips. Longer trips also meant we had to start carrying more stuff as we needed to be self sufficient for longer periods (IE: dog stuff, truck parts, tools, etc) and we never knew what type of support we would get at far away sites (ie: will just the 3" slinky do?or do we need the macerator and hoses too? Johnny bucket? How long of a water line? power extension cords? etc, etc...)
Of course during all this the cars/trucks kept getting bigger also. Right now we're into a 1998 3/4 ton GMC 4x4 diesel:
We've probably "topped out" on how big we will go. This will probably be a "10 year" camper for us. I have learned to "never say never" though. I'm only 47b (wifey is 37) and we already find ourselves looking at the huge 5th wheels with double slides and laundry facilities thinking that in ten or so years and retirement it might be nice to do some serious snowbirding.....which will also mean a 1 ton or larger tow vehicle.
To me, camping is limited by two factors: what you need and economics.
If you don't need any more than a pop up, you're good with a smaller unit and a smaller tow vehicle. That's not a bad thing, there's a lot of pluses to smaller (IE: less expensive, more options, easier towing, easier on the tow vehicle, easier to take to less developed sites, etc)) setup.
If you can't afford a big trailer or a big tow vehicle, you're limited to a smaller unit. It's my experience though that most would opt for the larger units if they could. Not all, but most.
Either way, as long as You're comfortable and happy with what you've got, nothing else really matters....