What’s not to like except for small size and associated limited capacities?
There is less living space, less storage, less fresh water, less holding tank capacities, etc. However, by accepting “less” space and capacities, owners get many advantages that may or may not be important to others. Trade offs are extremely subjective depending on wants and needs.
I can list a few advantages “important to me” compared to previous Class C, in no particular order:
Park at home
Use as second car
Doubled fuel economy
Much easier to service and maintain
Park anywhere
Drive places large motorhomes can not
Easier to drive (less tiring)
Requires less trip planning
Don’t require toad
Quieter
Fits in any campsite
Easier to wash
Full body paint standard
Lower overall cost
Fewer/no leaks
Etc....
From my perspective everything about a van-size RV is better except for lack of space and associated capacities, and no one else can judge how much another person needs or wants. My wife and I are both relatively small and don’t need a lot of space, and more importantly don’t mind working around each other to move around. We also tour more than camp, which makes big difference. Also, in my opinion, level of vehicle build luxury is irrelevant to downsizing decision. If you can’t survive in a small space, gold platting it won’t help, so throwing money at it is likely a waste.
For the traveling we do, a house on wheels doesn’t make as much sense to us as a van we can sleep in. The freedom of a small vehicle has more value than added space.
P.S. — By definition Class B (van camper) can range from very small with pop-up roof and no bathroom, to 24-foot high-roof Mercedes Sprinter with full dry bath. Just stating that not all Class Bs are even close to the same, so there is much to consider and choose from beyond it just being a “B”.