Most of the time I am in a 1BR, it is just two of us. I will squeeze three---me, my partner, and one adult child---but that's unusual. Once we get to four, the 2BR is the minimum viable size.
For me, the vacation experience in a villa is just much more pleasant than in a studio. I will do a studio for a long weekend, but that's about my limit. Anything longer and I want a living room and the amenities of a Villa.
Is it more expensive? You bet. Is it a "bad" value? Not for me. I do not care that it costs double the points of a studio. Well, I care, but it doesn't make any difference. I did not buy a timeshare to stay in a glorified hotel room for a week. On the other hand, I do not want (or need) to stuff the unit. I like my elbow room.
Here's the easiest way to describe it: If I am at WDW for a week, I would rather stay offsite at Bonnet Creek in a 1BR than in a single hotel room or studio onsite.