I had a cat that had very thick fur. In the summer it bothered him a lot, and matted horribly So, I had the “lion cut” done for him. I did not think it cruel, I know he felt much better once I had that done.
Seconded. My long-haired cat loves lion cuts.
We have a schnauzer / poodle + unknown others mix. His hair is a problem for him. Way too thick and prone to matting. He loves a short haircut every couple of months. His is not a good mix plus his bark sets your teeth to hurting. He was an elderly neighbor’s pet and we took him when she had to go into a nursing home.
No haircut would be the cruel thing.