Ask HN: How can I demonstrate value as an onshore developer?

I was recently told something along the lines of:

"You have to really show you're adding value, because you cost 3 times more than a Romanian dev"

I find this pretty intimidating, but the reality is that it's a difficult statement to argue with.

What can I do to prove my value?

Furthermore, is it inevitable that junior dev jobs in high-cost-of-living countries will become scarce? My own employer seems to favour the model of having a handful of developers/team leads in the UK, with the majority of the team offshore. I'm beginning to wonder whether I need to either change careers or move to a cheaper country (the latter option being slightly more doubtful now thanks to Brexit).