Those who left a comfortable firm, what helped you actually pull the trigger?

For those who’ve left a comfortable setup w/ lower billables, short commute, nice colleagues, etc. for a more established firm (not big law), chasing better mentorship, more sophisticated deals, and actually learning your practice area with experts, what helped you make the decision?

For context I’m a corporate associate about 2 years in. Current target is 1400, and new opportunity is 1600 with a 25K raise. My current firm treats me really well. Everyone is kind and respectful, and honestly that’s what makes leaving hard, more than the hours or the commute. There just isn’t enough work here though in what I want to do (commercial and m&a). The new job is a clear step up in work quality and availability, but I keep hearing that more demanding firms come with harsher personalities and less patience.

I know it may sound juvenile to some, but I’m being as honest as I can. How did you deal with the uncertainty, the anxiety of leaving something you know for the risk of the unknown? Did you find the reputation for harsher personalities at bigger firms true, or overblown? And if you landed under a difficult partner, was the work worth it anyway?

I don’t have many lawyer friends, let alone any in firms where they could provide insight, so really appreciate any input!