I guess I find a lot in common with your story.
I just completed 23 years with the same company. While I have had “promotions”, I have not changed classifications or moved jobs in at least 10 yrs.
I have been working on one project for 17.5 yrs.
When I started with the company, I was called a specialist (non-management) and was working in the marketing department. I was the only technology person, so everyone came to me. After a year and a half, I got promoted but mainly because a contractor I was working with quit because they were not paying him enough and they were afraid of losing me.
After another year, I moved to the marketing information group, there I was one of many tech people, so I was not so “special”. I made a couple of moves, but was put on a project to improve some guys antiquated process (move from Access to SQL Server for the build), but then when they decided to build the web version, they gave it to a contractor and another employee. I was needed to keep working on the existing process (legacy).
When they got ready to release the web version, they did, and they turned it over to me to maintain. I had to re-write lots of it because it sucked. I have maintained that legacy code since then (the 17.5 yr project).
I have developed some new stuff over the years, but honestly the last new thing I developed was over 10 yrs ago. I basically maintain other people’s stuff or stuff I wrote more than 10 yrs ago.
I pointed out about a year ago that I was qualified for a manager job that had been vacated and I had no option to interview for (it was filled before I knew it was available), they seemed shocked that I was interested. A manager spot came open in another group so they recommended me (but said they would hate to see me go). I did not get that job (I do not believe I was torpedoed, but that the hiring guy found me too old, I am 47). So I have sort of settled back into my regular routine.
I could leave my company, but I get full retirement in 8 more years. I would be giving up a lot to leave and honestly I am not sure I want the hassles of a new job.
I am good at what I do. I do wonder if I would have reasonable skills at other places (I am a database analyst using SQL Server). But I know the guys I work with, I work well with them. I can work from home a couple of days a week and I make pretty good money doing what I do.
I might be a Milton, but at 55 I can retire and live at the beach (ok, maybe not at the beach, but it would be a decent retirement).
I guess for me, being comfortable in being Milton is a good thing.
My word for you is, it may not be that people don’t like you. But IIRC, like you, I do not hang out with my fellow co-workers/managers, I just do my job and do it well, but don’t rock the boat. So, since everyone cannot be promoted, keep me relatively happy doing what I do, and try to appease the ones that push to be promoted (most end up wishing they had not been promoted, it is a lot of extra hassle for very little extra money).