Am engineer. Can confirm. Things that I can't prove definitively contribute to this in engineering but pretty sure do to one extent or another.

• pensions. We used to have them. Now most don't. 401k is portable. Companies never adjusted to a guy wanting to stick around for the pension.

• hr/recruitment. They get paid more and have more work if there is more change. So they don't let raises get to high and then obfuscate the costs of bringing a replacement in (starting out inefficiency, cost of hr/recruitment, etc.)

• safeness. The thing you describe as feeling insecure and wanting to "commit" to a company. They know they will keep some % of the people like you. At a discount. So it helps balance the books. (don't get me wrong. I think after my last move I am going to be like you too. I make enough that I can be comfortable and live within my means and so the extra $ isn't as big a factor.)