This one is very obvious. It's not specific to the tech world. Companies know that changing jobs is stressful, that there's value in remaining where you are, and quite obviously many people are willing to accept smaller raises so that they don't have to go out and apply. For most jobs in the world, you can't work remotely, and renting a different place or selling and buying property is time consuming, stressful, and expensive. In other words, this is common sense economic reasoning.

One side point is that if you can work mostly or entirely from home, that gets rid of some of the pressure to stay where you are, which in turn should create more mobility, which in turn should create more pay raises for employees who stay. But work from home is relatively the recent phenomenon, so old company pay scales are unlikely to properly account for it.

Another point, that the author completely overlooks, is that some people don't contribute as much as the author thinks they contribute. If they know that, of course they don't want to move to a place that does contribution-based pay. They could get hired on somewhere during a probational period of some kind, and their new bosses might think they're not good enough, and now they are out two jobs. Of course the turnover on their second job makes their resume look weaker, so they'll have more trouble finding a decent third job.

None of what I wrote is new information. It seems like the author of the article did that standard thing in tech circles. They decided to reinvent the wheel and write about it, and try to make it exciting when it's not. Good for them for examining the problem, but they should be slightly embarrassed for publishing before doing basic research to see if someone had already addressed the question at hand.