I once had a conversation with a elderly Yorkshire bee keeper.
He told me that in his village, he heard there was a woman suffering from with stomach ulcers.
Conventional medicine had not helped much, and she was in a lot of pain.
He genuinely believed that she was slowly dying from the effect of the ulcers.
He went to see the woman.
He said he would give her honey from his hives at no charge, as he believed it would help her.
He told her she had to eat it every day.
Over the period of a few weeks, her condition improved a lot and she became well again.
He told me that in his opinion, Manuka Honey was neither better nor worse than other wild honeys in it's medical effectiveness.
He said it was more expensive though.
He had no business reason to say this, as he did not give me details of how to purchase his honey.
The subject needs extensive tests on a variety of honeys on a variety of conditions.
This 2018 test suggests Manuka Honey
is more effective than other honeys.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6613335/
The test's CONCLUSION: The research data has confirmed that Manuka honey's antibacterial activity, in comparison to non-Manuka honey, is due to a higher phenolic and methylglyoxal content."