Rabbit people are interesting. There is the "pet" crowd who want them to be free ranging house bunnies or in giant enclosures. And then there are hardcore breeders who keep them in small cages. and then lots of in betweens.
A breeder I am friends with and respect keeps her in cages 24/7, absolutely no treats, greens, etc. Her bunnies have never been on the grass or had a carrot. EVER. She prefers 18x24 cages (dwarf breeder) even for does with kits. Her bunnies are all healthy and happy and quite honestly friendlier than any of mine.
I have a pair of bunnies in a big tractor out back on the grass. 4x8 total....2 feet inside, 6 feet outside.
They dug out twice so I had to put wire on the bottom.
I also have bunnies in 18x30 cages inside the house currently. Wire with drop trays. They are tall so I can add a hammock or shelves eventually.
Plus bunnies outside in either 2x4 or 2x2 cages. Bucks are all in 2x2 on left. Does are in 2x4 on right. Over summer when the does were all inside, I had the left sides as full 2x4 also to let each buck have a condo out there
I give all of mine carrots and treats and even pull weeds for them.They got lots of hay, alfalfa cubes and best of all TOYS TOYS TOYS.
But the "pet" rabbit people would hate my setup. And breeder rabbit people would hate the pet setups. I'm kind of in the middle. Wish I could come up with a way to keep retired breeding does in a colony of sorts. Not sure how that would work without them trying to all kill each other. But for retirement, sure seems like a huge pen would be the best option for the ladies.