You can go into a clothing store and buy certain items such as baseball caps that are 'one size only', but when it comes to nutrition and fitness, there's no such thing as 'one size fits all'. Everyone is different, everyone has different needs and what works for one person won't necessarily work for another.
I follow a number of guys in tremendous shape - actors, athletes, personal trainers and guys who just love to workout. They upload their training routines, reps, sets, diets, supplements and so on. I always read them, I always note things down, but I never think 'I have to copy them perfectly', because even if I do, that doesn't mean i'll have a body like theirs. I do try things that others do, and to this day I still do things that I have learned from other people, but I have learned what my body responds to and I am always learning and understanding what works for me, and that is the most important thing.
It's not a bad thing to copy celebrities or athletes training routines, I'm sure you will get good results, but don't expect to look like that person after a few weeks of copying them. People do expect results to quick, especially if they copy someone who is in awesome shape. Genetics plays a large part - some people simply struggle to pack on lean muscle mass, others struggle to burn fat, others struggle to put on size.
You need to learn about your own body, learn what exercises are best, what sets and reps are best, nutrition and supplementation, and more. It is trial and error, but once you narrow down what is best for your body, you'll soon start seeing great results. It does take time, but i'ts well worth it.
So, it's fine to copy others who are in great shape, but don't expect to look like them after copying them. Learn about your own body, learn what you respond to best, and train smart.
Lee Gregory Fitness