It's not a 1 size fits all kinda thing.
The 1 size fits all only really works with hats and scarfs.
To be honest there are a lot of similarities between people but what works for mum Laura might not work for mum Nancy.
Relying on what works for your friend isn't always the best way to go. For example Mum Laura might prefer eggs at breakfast, Mum Nancy might like porridge. Ones high protein and fat the other is high carb. Neither is wrong granted they have a balanced diet the rest of the day.
Mum Laura might prefer lifting weights, Mum Nancy might prefer interval training. Both have merit.
The point is we sometimes heavily rely on what people around us are doing when we haven't actually put in a lot of effort to find out what will work for ourselves.
What's the harm with experimenting?