Background:
I am in a role with a title that is way below my abilities and actual responsibilities.
My previous manager took a better job within my organisation. Prior to this, she tried to get me a promotion. This was about to happen (about a year ago) when suddenly a new companywide policy came into effect which makes it impossible to get a promotion without changing roles.
My new manager is relatively nice and my work life balance is normally ok. I have a lot of freedom to be present for my 9 year old, who needs a lot of support due to my abusive ex/their father. I am getting a bit bored with the job but it's fine.
My old manager called me recently to ask if I want a role in her team. I would be reporting to a young and keen person (without kids) who is leading a new initiative. The work sounds very interesting and suited to me, and this would give me a broader range of experience. I would either get a higher job title or (more likely) a significant pay rise.
I'm in my late 40s and I am getting anxious about what opportunities would be available if I were to lose my current job or just find that I couldn't stand it anymore.
YABU - Stay in your current manageable role and enjoy your good QOL.
YANBU - Take the opportunity, even with the possible risk of a strict manager, and that the role may be super demanding.