thepianoplayer416 Unless someone is a professional who performs regularly, even those who passed music conservatory exams at a high level isn't at the level of the world's top performers.
This is the thing. 'Level' is very broad. There are probably infinite states of 'high level' in the music and piano playing area - as it extends in various directions.
Everyone is different from each other. The way you (we, I) think and do is different from the way other people think and do etc.
For example, a 'top' performer might be good or great in their way. But you (we, I) are also good or great (even though my focus was never about being good or great or special or anything like that) - in our way. That's because everyone is different from each other. They are not you, and you are not them.
Overall - it is broad, because each person has their own state - which keeps changing and building as time goes by - and it is going to be a combination of their accumulated skills, including theory and application of theory and experience, plus also an extra x-factor which probably involves their own personal life experience and own internal potential and brain functions.
Even if someone practises and performs (which is pretty much practising as well, as even performing does count as a form of 'practice' - practising the art) on one particular sort of piano, then that's great - because (if they want to later) they can also enjoy practising and performing on another sort of piano. As is known - people both practise and perform on pianos all the time - on acoustic pianos and digital pianos etc.
People are generally flexible and adaptable. When they practise and develop adequately, and have experience on the various sorts of pianos, then they can assess or check out the behaviour of their or other instrument, and then adjust/adapt. It's part of learning too - and if someone is unaware of what features or sound or details to look/listen for, then particular teachers can point out what to look/listen for, and what to do. Part of the learning and developing. Ongoing processes. The keeping on with the learning and developing is what I find very nice about piano and music.
When it comes to music and pianos and people - there is no 'the best'. No one or type of piano or music or person is overall better than another, or best.
Also - if family members or relatives or friends gave up piano for some reason, such as they got forced or pressured too much, then that's fine, and no problem, as their skills will still be retained within them, or can be regained --- for when they are not pressured anymore. And a lot will return to playing piano again after a while - no matter how long that while is, and that is great.