I thought there was no-one else on the market? If you think it will kill the visa program, that means you thought hiring underpaid developers was the goal of the visa program. No-one would change companies if if get paid decently: You leave a bad boss, but you can stay with a with a 10-15% lower-than-market salary just because of the friction of changing (Cue the downvotes: “I’m changing for a cent more” - yes you do when you have energy but most employees absolutely don’t). And employees will stay because they need time to settle in the new country and the welcoming company is generally equipped to make integration easier for newcomers.