I know people who had DC at Stowe and, it’s like everywhere else! The parents vary.
I would say though, that all independent schools fund raise. Many have private dinners for bigger donors and their richer parents who can be tapped for money. The schools delve into who they are! Rugby have the Arnold Foundation and other schools have similar. They often raise money for bursaries for example. Therefore the idea that every parent is the same will not be true. There are definitely preferential parents! That doesn’t make them obnoxious.
At many independent schools there are opportunities for parents to meet. Some like to and some don’t. We found the very rich don’t. If they do show up, they have their own set and have arranged to be with them. You can fairly easily twig what’s going on and get on with your life.
If you go to a decent prep, look at the other schools where the girls go. That’s what happened at my DDs prep. So WA, CLC, Downe House (Head was a Governor at our prep), Benendon and a smattering of co-Ed’s such as Stowe, Oundle and Uppingham were favourites. The prep school will know the time of day regarding applying and will offer guidance. All independents value academics! They all value parental money too!
Parents send drivers to pick DC up for exeats for example. It’s not that they are overtly showy, they just quietly have the money to do exactly what they want and employ people to do things many parents would do themselves. Their world is different.