Ask HN: Career Advice

I'm working on the same company from nearly 3 years as Senior Software Engineer, around 2 years ago I started having talks with the manager of that time to move to a Lead position, made various plans and one of them was to do something significant for the company. I had an idea in mind on how to improve the architecture of the frontend part of the company application, I expose the idea to a couple of colleagues, and with some brainstorming the idea becomes a presentation, I present the presentation first to the manager then to the CTO. Fast forward 6 months and a team was created to make this idea a reality, in few words the project is to transform the frontend from a big monolith into micro-frontends, the project includes creating tools to make that happen, a proof-of-concept split of the monolith, and best practices to keep everything working properly and tidy. The created team at the beginning was composed by: 1 developer ( myself ), 1 product owner, 1 scrum master and 1 manager. As I joined this new team I had to change manager. The promise was that more developers will join the team in the future. After 2 months two developers join the team, one month after the leave the company for reasons unrelated to the work being done ( one of the developer wanted to become a doctor, the other was his best friend and followed ). Two months later another developer join the team, he leaves the company after 2 months because the job was too hard compared to the previous team. Another six months pass and new hire joins the team, this was 5 months ago. During this one year and half I had constant talks with my new manager about the Lead position ( that then became Staff Engineer position ), all that happen were talks talks and only talks, no action whatsover. The justification for the impossibility to move that position is that I need to show managerial skill over a big number of developers and unfortunately my team is composed by only two developers and the other teams grew very independent from us, and the reason why other teams are independent is because we did a good job at documenting everything and setting up the tools and the new micro-frontends so best practices are natural to follow, at the beginning the other teams did approach us with questions and need for direction but in the last 4 months this has become very very rare. The worst part is that everyone in my previous team had a promotion, all the juniors are now Mid or Senior, and the other Senior developer is now Lead ( we were only two senior in the previous team 1 year and half ago ). I honestly don't know what to do anymore, I feel like I hit a brick wall, I talk about this with my manager every two weeks and he always says something will be done. Work has become de-motivating, I ended up in the team that does one of the hardest work in the company and that every other team now depends on, and this has only set me back. I tried to move back to the previous team but they don't let me because I'm the person with the highest knowledge of how the architecture of the app and it's inner workings.