For me, I feel like we’ve had so much ‘positive utopia’ Trek, that more of the same just gets a bit boring. There’s also the fact that life today is different compared to when Trek first aired. We’re more aware of some of those sharper edges and want to see them represented in media.
From a practical standpoint, there’s also ‘we can, so we do’. When Trek aired on regular TV, you couldn’t drop an F-bomb, much less show actual gritty stuff. With streaming, there’s no reason to hold back. Which gives writers more room to explore.