I don’t know what your seniority is, but it’s cool if it works for you. However, to remain employable in case you someday get laid off (of course not wishing you that), it would be beneficial to have experience in a more modern language. To remain fixated on one single language/tech just because it works for you for now is going to cause you lots of pain in case you need to hit the job market again someday and it would be too late to learn new languages because, depending on your seniority again, recruiters won’t want someone who just began learning the language.