[havnagiggle]

A lot of my team switched product areas when they needed to spice things up. They had a wide range of years on my team, from 2 to 10 years, and AFAIK there was no stigma attached to it. Have you considered that? If you are an IC, they might have some small project in mind for you to test the waters that it's a good fit. Maybe your manager is giving you the run around because there is just not much growth available in your area. Generally managers _want_ to promote because it makes them more important.

Do you have meetings with your skip manager? It sounds like your manager is not going to bat for you. I have had to drive my own promotions at various times in my career. I am not interested in leadership though, and that's a pretty different skill set. If that's of interest, you may need to actually cut things that don't better demonstrate that skill as best you can.

Do you have a FIRE number? I won't be leaving this cushy gig until I hit my number, but I do have a number. It has helped me time box my working career. I don't really need to be above-and-beyond satisfied with my job because that's not why I am working. I do get that being interested in the work helps the time pass, but IMO that's a double edged sword. People that care too much tend to get sucked into more responsibilities, which in turn can cause a brittle team dynamic with too much landing on one person. Of course experience and personalities vary.

For me, I would easily get obsessive if I were to start my own company and it would not be in a healthy way. I have also had too many friends try the startup route and really paid the price in a stagnated career. With a clear path to FIRE it's just not worth the risk IMO. I have family and plenty of hobbies to enjoy my time until then.

Good luck!