Is "This is more better than the last one" correct?

Why

Vishal's instinct that adding a word makes something feel more emphasised is understandable — in ordinary conversation, saying more of something often does mean more emphasis. But "better" is already a complete comparative form of "good" all by itself, carrying the comparison inside the word itself, the same job "more" would otherwise do. Adding "more" in front of "better" doesn't strengthen it, it duplicates a job that's already been done — the equivalent of saying "more gooder", stacking two comparison markers where the sentence only needs one. This is called a double comparative, and it's treated as an error precisely because it repeats work the word has already finished. Test: notice you'd never say "more taller" or "more faster" alongside a regular "-er" comparative, for the same reason — the comparison only needs marking once, whichever way it's marked. His teacher is right: "better" already means "more good", so "more better" repeats the comparison — it should simply be "better".