Apparently I'm the dumbest person in the room and I haven't been told yet

Hello, I hope you are all well. I'm writing this somewhat frustrated, as I don't know exactly what I'm doing wrong.

I have been a software developer since 2018 and have been doing in backend development. I have 4 cloud certifications with near perfect scores. I am fluent in two languages, in addition to my native language, and have three bachelor's degrees (humanities and sciences). My cultural capital is above the norm. I've been successful in two of my previous jobs (not just normal kudos, but what I've done has made my former workplaces money, international clients, become cloud service provider partners, opened up to the public sector).

Now I work in a company where my bosses have been changed at least four times since I have worked here, and there is no consensus in the evaluations I have received, because some bosses are involved and others are not, as they know that they will soon be leaving for other teams and that leading us is transitory.

I do everything necessary to contribute: I help my colleagues, ask questions, take notes, talk to our end users, report to managers, show up whenever I am needed, keep our documentation up to date, discuss ideas, solutions. Everything. I've improved my productivity, my ability to focus, the way I do reviews, the way I deliver.

But it's been three years. No pay raises, no promotions. The current boss says he is happy with me. I have asked for more money this year twice: January and July. A big NO. Boss says "sorry, not this month, I've tried everything, I don't understand what's going on, but keep it up xoxo". I don't know if he tried or not, but I'm sure he just doesn't want me to get mad at him, so he has this soft attitude towards my needs. Also, none of my coworkers (except for the most senior one) have had pay raises, or promotions. My coworkers say my work is very good and they are pleased to have me on the team.

So of course there must be something else.

I've even come to think that maybe I'm retarded, or have some kind of mental deficiency that doesn't allow me to thrive going forward. Maybe I just don't fit into the software world and should pursue something else. But at the same time, I've invested 5 years of my life into this, so I don't want to throw it away.

Besides, I'm not a smartass who says "everyone is an idiot but me".

There's a saying that if you're the smartest person in the room, you're in the wrong place. But what if maybe you're the dumbest person on the team?

I don't want to change jobs and find more money and promotions somewhere else. I want to master and overcome my current situation, otherwise I'll drag this problem into my next job.

What do you think?