I agree entirely. Your point about going back to the tried, tested, and liked things of life resonate with me a lot. Why is it considered such a good thing to be uncomfortable?
Personally, my goal in life is to be happy and if I'm happy doing things I'm most comfortable with, why strain to try and be uncomfortable? As long as one is happy, who cares?
I get the point that if you never try anything new, you will never know if you might be maybe happier by doing something different, and that's why I like to experiment with new things. But if I find I don't like something, it could be the best growth tool ever but I won't do it again.