There is nothing wrong with sticking to one company and a somewhat static job role if it meets your needs.

Switching jobs will be uncomfortable, carry risks, and will have a lot ot unknowns. Maybe it was the best decision ever, maybe it was terrible, maybe it doesn't move the needle.

An even bigger move is quitting your job and starting a business. All the risks, rewards, and stresses are exponential.

There is no right decision, it's personal choice.

Anytime you take a chance and make a big change it will scare you and that's normal. As long as you've thought through the worst case scenario and have a legit plan on how you would deal and overcome that, then make the leap. Don't let fear be a factor. Be logical and realistic, but don't let fear into the equation.

I went from stable situation to changing jobs for a few years and eventually entrepreneurship. It's been a rollercoaster of excitement, dread, success, failure, and everything in-between. It hasn't been boring, and I feel like I'm more in control of my life...for better or worse.

On the flip side, I see many happy people who have been with an employer for 20+ years who are comfortable, secure, and generally happy with their work. These people seem to be a little more well balanced with hobbies, family, etc due to their life being so scheduled and predictable.

Sounds like you are deciding between two great options. Whether you stay or go, it will likely all work out one way or another.