I’ve worked at 5 different companies in the last 5 years since finishing University and it hasn’t been an issue with recruiters. I’ve been able to almost triple the salary I got in my first job. I’m hoping to stay a while at my current place, but you never know how things turn out. When you feel like the job is unhealthy for you or that you have better prospects elsewhere, there’s no reason to stay.
Employers are not loyal towards employees and will fire them without blinking an eye the moment they need to prop up their stock value. I don’t see why employees should feel any different towards employers. It’s business.