I used to think that way, but in general, the situation will change. You can have a this awesome job for N years, and then management can change and you'll be miserable.
I think it's always better to be in a position where you know you can easily move if things go south. If your current awesome job is also making you grow, then great! If, however, it's too comfortable and you cannot differentiate yourself well, you will not be able to move easily once things go south.
You should seriously consider interviewing at other companies, where you should directly ask your interviewers questions about these topics, explain why you value them in your current role, and ask how this new company handles the same things. You can find stimulating work at a lot of places if you look hard enough...
Non-glamorous startup problems, am I right?
I do wish I could move, however.
don't worry about it. You aren't underpaid because your job has other benefits that are worth a small amount of money. Or look around for a competitive job that has similar benefits and better pay