How important is moisturizer beyond moisturizing? [routine help]

There are a range of moisturizers from bare for sensitive skin, to high end and pricey. My question is:

Does it have major effects or is it truly just about finding something that moisturizes and doesn’t irritate your face?

Then for actual change/results we want to look into active ingredients?

I just wanna know if I’m overcomplicating or over-paying for moisturizer when it’s really not that serious.. or if it does make a big difference!

Thanks for help and experience!