This is not true, and just taking a dab on a fellow engineer looking for a job is not cool or funny. With that out of the way, most boring (insurance, e-shops,

This is not true, and just taking a dab on a fellow engineer looking for a job is not cool or funny. With that out of the way, most boring (insurance, e-shops, healthcare, logistic, etc...) don't care about keeping anyone(tech) around, so the "if you are good enough, companies will try to keep you" is a lie, at least in the US. Anyone can pickup their tech stack fairly quick. The technique I have seen some "boring" companies use, is to hire very junior folks , convince them they are making progress in their careers , promoting them to SDE1, 2, Senior SDE, Team Lead, etc... (and raising their compensation to a 3-5% each time, and making it a big deal) which means very little if your company doesn't have real infra. Many people settle for a familiar environment(sometimes the only they know) that pays them just enough. In big tech is a bit different(in my experience from Amazon, Msft and Google) , they do have "Dive & Save" money, to keep you from going to the competition.