Like many have said, it depends on your goals. Do you want to have career success, a little more change in your pocket, and additional responsibilities, or do you value your time off to do hobbies and a more relaxed mind set?
Also, as others mentioned you have to evaluate your current company’s culture and the leadership you currently or may in the future report into. If you dont care for your current company, then it may be time to go. However, if the current company has never given you a reason to dislike it or leave, consider that as well.
I think you are in the best position you could ask for since you have options.
If your current company didn’t value you and your work, they wouldn’t have offered you a promotion.
If you want to grow in your career, I’d suggest letting your current company know that you were offered more money for less responsibilities at the competitors company. Sounds like they already know you’ve been bored so it shouldn’t surprise them that you were exploring your options. By telling thiem about the competitors offer they may increase the salary that they initially offered you.
If you take the role with a better title and responsibilities, you can always go back to a lower role and reduction in pay. However, it’s not always easy or timely to move up.
If you decide to stay with your current company, i don’t think the competitor would blame you if they said that you decided to stay after the existing company offered you a leadership role and a bump in salary. In fact that may make them want you even more if they know that your existing company values you enough to keep you.
Whatever you decide to do, keep communication open with both companies and don’t burn bridges. You may want to reach back out to ether in the future if looking for something different down the road.