To some degree, you need to find a fit. If people aren't looking for polymer, you cant force them to use it or seek it.
I would instead look at what is currently out there on freelance sites to get a better idea of what type of requests are paying the price you want.
I too am a UI dev and I almost never hear polymer brought up anymore. It's angular/vue/react/ember. Which changes this situation to look at how things are opposed to how they should be or how you want them to be.
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