There reaches a point in a job that you are no more valuable to the company than you were the year before. You become worse after a certain point as opposed to better. Have you flown with a 25 year lifer at a regional? They are terrible.
The regionals are not supposed to be a career destination. That is made clear every day. There are some people, however, that are too lazy to move on. If you are over 6 years of seniority at a regional, get the hell out. Move on. Go elsewhere.
They should start decreasing pay after 8 years just to force you to go to a real airline or go and get a job at Menards. If you are stuck at a regional now with that much seniority, you should not be flying an airplane.