They do. Job hopping every 1-2 years is pretty standard for software engineers, and it's pretty common for people to feel like the only way to get a significant raise is to get a new job.

I job hopped throughout my 20s, partially to increase my income but also because I was hoping to find a company that isn't dysfunctional. So far I haven't found one. The biggest problem with retention, IMO, is that the vast majority of companies are shiny-object chasing feature factories. The framework, language, and library churn is just exhausting and saps all the fun out of writing software.