I wrote an article on Loyalty a few years back while I was on an 11 month break:

https://battlepenguin.com/philosophy/society/loyalty/

I'm not very 'loyal' to jobs, often trading for adventures every once in a while. It's a double edge sword; it's easier to get hired at places that really push the edge and want really motivated people. But not having more than 3 years at a single place does make it difficult when trying to find new jobs. At the same time, I'm paid at market value, where if I stayed at one place 10 years, I'd likely be at least 1/3 under market.

An employer expects 2 week notice to provide continuity, but employees do not have that same expectation.

Obviously this is optional, but can stick with you if you need references.

My current contract is pretty typical requiring a months notice either way.