needs fat as an “ingredient” to build muscles

No, muscle protein synthesis needs amino-acids. Fat is not used to build muscle

Then burns preferably muscles

No

Fat is hard to convert

Not nearly as hard as it is for the body to atrophy muscle mass, turn the proteins into amino-acids, and turn those amino-acids into glucose and then ATP

protein (muscle) is easily accessible (bodybuilders take protein as supplement)

It isn’t, and the digestion of whey protein supplements can not be compared to muscle atrophy

You need excercise and not just starving to lose weight, no?

At this point I’m sure you’re just trolling, because that couldn’t be further from the truth

And btw, even just keeping muscles needs more energy

True

Fat not

Keeping fat cells also uses energy, just not nearly as much as muscle mass

If you wanna know my credibility on this topic I would suggest a look at my profile picture