"The universe is such that life could appear and thrive.

It's not at all the same as saying the universe was designed for life.

Is it luck if life appeared? A universe with different constants could be a lot more interesting than a universe where life exists."
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Yes it could be interestingly wildly different or quite uniform and bland, but as to the question of why our universe is the way it is and the seeming need for many constants to be just so for complex life to exist. Were any of several physical constants slightly different, stars could not form, etc.
Seeing that a universe with matter, gravitation, stars and very very fine-tuned constants allowing nucleosynthethis is this universe, how did that happen? Luck? Or are there an infinity of possible universi and we live in one of the infinities where life can exist? Or was it made this way?