At some point, you have to sit down and do the work with the tools you have if you want to get anything done. If I were to get serious about programming, I would use C# or Go because I found them the most accessible after trying lots of languages. There's nothing wrong with finding a niche.
Not only that, but knowing multiple languages has a multiplicative effect, massively expanding how you think of programming in all the languages you know, even the stable standbys like C#.
and yet... almost every time I've come in to a project where developers got past those boundaries.... they inevitably recreated patterns/idioms from tech 1 in to tech 2, and make tech 2 horrifically bad, and made it even harder for anyone who actually knew tech 2 to come in to the project and help.
adding other languages is more than just 'get over it' - without guidance from experienced people who can understand good/efficient ways to model the problem domains unique to a business idiomatically in the new tech, you're very likely adding even more technical debt that you won't even know about for months/years. And... IME, the "let's use new stack X" are moved on to another project or company by the time the technical debt is apparent to everyone.