Anyway, if you like what you're doing and are just wondering if it's safe, why not expand your skills rather than jump to a separate pond. To use metaphor: "increase size of your circle" or "learn something in an overlapping circle".
Also, I suggest expanding first in the area of fundamentals. You mentioned SQL: it has outlasted many fashionable programming languages and is likely to do so for quite a while. Or improve your on algorithms and DS skills a bit. This is because the "next language" is statistically going to last a short time, while the deeper skills will make you better with whatever the fashion of the day happens to be at some time in the future.