We do a few villa holidays - stayed in them across Europe and int he US, plus cottages in the UK. Have done so since DD was a baby and she is now 14y, only child. Sometimes we go alone, sometimes with family, sometimes with friends - our friends have DDs the same age as my DD who are good friends of hers too.
DD prefers villas to hotels - she never did the whole joining in with kids clubs or anything anyway, and likes to spend time with us rather than children she didn't know.
She just spends loads of time in the pool - sometimes alone, or with her dad or with family/friends if with them. She enjoys laying back and reading, and sunbathing, and also will use her tablet and the WIFI (she is a teen after all!) and then we enjoy some of each day exploring.
The villas we rent are usually fairly central and walking distance to the resort and/or beach, have a private pool, plenty of room, BBQ, WIFI, music systems, etc and we have car hire for exploring. Often they have a games room, and pool 'toys' and love not having to fight for a decent sun bed.
We eat out for all big meals. We do grab things like breakfast cereals and tea/coffee, plus alcohol and soft drinks, snacks, etc. So we will eat breakfast in, and some snacks. Depending on where we are we might get stuff for a BBQ or a big fresh salad and have that - but nothing that requires much prep, cooking intervention or time. Mostly we eat out.
We always ensure the villas have a cleaning option at the end, or that don't ask it to be left spotless. Never chosen one without a dishwasher either for that reason. I would always leave a hotel room tidy, so a villa is no different to me.
We would almost always choose a villa over a hotel.