A noun can only have one comparative.
More is a comparative.
- He has more wine than she has.
Adding –ier or –er to the end of a word also makes it a comparative.
- This wine is tastier than that one.
More and tastier are both comparatives so cannot be together.
This wine is more tastier than that bottle.- This wine is tastier than that wine.
She is more funnier than Tom is.- She is funnier than Tom is.