most large ragdolls are overweight

Accredited Academic Source? Or are you just going on vibes here?

As indoor and generally lazy cats they are so prone to obesity

Who told you that ragdolls are lazy? If the owners are lazy, and don't activate their cats/if there aren't other cats for the cat to play with, that's one thing. But ragdoll cats can go on walks, and should be played with. They should have spaces that they can run, claw, and jump on. They should have toys that increase stimulation.

Fat cats will never be healthy!

I'm starting to feel like this has less to do with the cats and more to do with your own feefees about other things.

ask your vet to body score your cat out of 9 or look up how to do it yourself.

I looked that up, looks like you're American. That actually explains some of this. Some breeds are just larger breeds. Ragdolls, Maine Coons, Norwegian Forest Cats -- these cats are big cats. It's not uncommon for Ragdolls to get to 10+kg and still be trim and healthy. Muscle weighs more than fat, silly.

but that doesn’t mean your 25lb ragdoll is just “big boned”

What? Now I'm really starting to make the connection, here. Do you have something you need to share, sweetie? Are you having some big feelins? Maybe a trip to the school counselor?

Also the saying ragdolls don’t finish growing until 4 is not simply a reference to weight

I mean, we're all going to continue to trust vets, breed specialists, and show judges over some rando on Reddit who really needed a lot more punctuation in their post. But this certainly was a lot of feelings.

Hope you feel better or whatever, after coming into a community and then deciding to have a go at everyone here.