lets not ,its specualtion and not facts.
Some scientists disagree with them
And the extra protein doesnt build any additional muscle.
Have you not been following anything I have written?
Yes I've read everything and I try to remember it too as well as I can. The protein in elderly is to stave off sarcopenia. Fun fact I read recently, there's a thigh muscle that at about 80 years old is a big as a 5 year old's

I'd have to check but in my recollection some weight lifting can build a little extra muscle and especially strength.
I didn't go beyond this:
AI overview
Yes, a 70-year-old can absolutely build muscle through consistent strength training, even starting from scratch. While muscle loss can accelerate with age, muscles remain responsive to the stress of exercise, and gains in strength and size are possible at any age. Research indicates that people in their 70s and 80s can achieve significant strength gains and improvements in muscle mass, balance, and overall function. It's going to be relatively small but anything is better than nothing

I've tried encouraging my 77 year old mom to go to the gym twice weekly with her 79 year old husband (he does it). She used to but motivation is lacking. I tried to get her to drink a small 20 gram protein shake a day but she's picky with food.