I'm too tired to look it up, but I remember someone saying that resilience or grit was one of the best indicators of success. Someone replied that actually the best indicator of success is if you came from wealth.
Also grit is an over hyped and under delivered construct of human cognition that really is only spoken of seriously nowadays by people trying to sell you something
grit makes me think of Bukowski novels like Post Office. Just a bunch of dudes laboring to look like they're working hard to please the boss, rather than to do the labor.
Personally grit makes me think of literal sand. Or dirt in general. It's something you wash off the first chance you get. Not exactly something to be celebrated.