I honestly don't think being too selfless is an adequate explanation for career stagnation though. Selfless behavior will generally help you get ahead in life and in your career, because good relationships matter a lot. However you won't get promoted just because you help everyone. What if you are just servicing the squeaky wheels rather than solving the biggest problem on your plate? A good manager will only look to promote you because you have demonstrated you are capable of solving larger problems. There are other things too: like the business actually has the need for a higher level role. If that's the case, then your behavior is irrelevant—you just need to leave to someplace that does have the growth opportunity.

Overall the reason I said your comment was strange is because it clearly comes from some personal experience you had, but it lacks enough context to be actionable to anyone who reads it. I can think of a dozen different ways I've seen a "servant leader" mentality succeed or fail, but it all depends very much on context. Ultimately if you want to succeed you need to understand what game is being played and not fallback to abstract platitudes.