I've been a programmer for 30 years, and I could reasonably be considered to be a senior dev.
Yes, I'm very happy with my job. I work at a company which cares deeply about solving hard problems well, and that care translates into good working conditions, great work/life balance, support from management for engineering concerns, and a very nice benefits package. There is also a focus on having separate promotion tracks for managers vs. more technically inclined people.
There have been jobs where I have either tired of the novelty of the problems, changes in management, changes in company policy, etc., but at that point I find a new job in a better company and continue to find happiness.
If you're not happy where you are, and you are considered a senior dev, then take responsibility for yourself and find a position that you enjoy. If you're locked into a company because of golden handcuffs, lack of local resources, or family obligations, then find activities outside of work that provide what you're missing.