The guitar playing is a good analogy here. Say you've played classical for years and dabbled in rock and some jazz. Like any musician you've played around a little but probably focus on one style. You're best friend asks you to play flemanco for them at their wedding.
Sure, you won't be as good as someone that's played flemanco all their life. But if flemanco was invented 5 years ago you're sure going to pick it up fast and probably be better than someone who has only been playing it for the past few years.
Skills translate. Transfer learning is unsurprisingly a real thing. The funny thing is that a guitar player will pick up a brand new instrument and quickly gain and surpass someone who has only been playing that instrument for a few years. Even though each instrument is a different "language" per say, there are common patterns in the language tree of music. I don't think any programmer worth their salt would disagree that this is also true for programming.
No matter the language you use, there are common patterns. Someone who has been programing for years generally picks up a new language quickly (because of this). Certain languages will make you a better programmer in general too (low level languages help you understand what's going on behind the curtain).
So should a programmer with 30 years of experience in C and 1 year in rust be paid more than the programmer with 5 years of rust experience? Absolutely. Those 30 years they were learning to program, to debug, to solve problems. The skills translate. And I say this as someone under 30. I've seen the wizards solve problems in languages they've never used because they just understand programming.