What!? In what world is muscle not a good thing. Muscle mass is even a measure of health in aging that fairly well predicts longevity.
Where did you get these ideas from?
Keto is supposed to be high fat, very low carb, reasonable protein. As another poster named it, medical keto, is hard to follow because of the high fat. Popular keto is still challenging.
It really isn't, it's just a matter of adapting your taste buds. If you're used to fries and muffins daily, yeah it can be hard, but as someone from Southern Europe used to snacking on salami and cheese and butter, reaching 80% calories from fat isn't hard at all, especially considering that fat is more than 2x more calorie dense per gram than protein and carbs, so you don't need that much of it. A steak with a little butter gets you there easily.