That hasn't been my experience. Stringify is/was a terrific tool, but I'm amply satisfied with my migration to Hubitat -- I've recreated all of my flows as locally run automations.
I'm really grateful for having used Stringify for ~3 years. When I made the decision to move to locally run/controlled automations in February, I thought it would be very difficult to duplicate the functionality of my ~80-100 flows. There was definitely a learning curve, and it didn't happen overnight, but 2 months later, I don't miss Stringify.
What I will miss more than the app itself is this community, especially @Kris; when he gave examples of flows or dissected complex flows, it was a great opportunity to learn Boolean logic.