It's a valuable practice, in and out of the gym.
It's one of the reasons a physical practice is so transformative: it locates intangible qualities in the realm of the physical.
And if you want to progress, you have to unsettle yourself.
Think about it: when was the last time you grew - in the gym or otherwise - without challenging your potential? Without amending what you already knew? Without admitting you were wrong? Without modifying your views?
Without doing something that you haven't done before ?
That goes for the realm of the physical as much as it does for our ideas, thoughts, opinions, habits...
Of course, that's never possible if you believe you're the expert or that you know the one right way. There are plenty of creative, useful, generous ways that are all good enough to embrace and celebrate, because one size never fits all.
The trick lies not in how rigidly you can cement your position, but in how readily you're able to unsettle yourself in the pursuit of growth.