[moondowner]

Plus in some companies it's very hard to advance, so it's crucial with which position you start.

There are cases where people go from one company (A) to another (B), and then after some time get back at A and get a better position. If they stayed at the same company the whole time they wouldn't be able to do that.

[potatolicious]

Exactly this. I left one of my previous employers after I got passed over a second time for a SDE1 -> SDE2 jump. It's been two years since I left the company and I've been repeatedly approached by their recruiters for SDE3 positions ;)

Sticking around for promotions is a fool's errand.

[mooreds]

Wow. If that doesn't scream "broken system!", I don't what does.