Everyone should be operating in their own best interest. If it's in the company's best interest to raise your pay to keep you on, they will. If it's in your best interest to leave, you should.

Some of my favorite career advice is to seek out a minimum of one interview per year. This lets you see what skills are in demand, what salaries are being offered, and practice your interviewing skills. It's a great way to educate yourself and improve long term career growth.