DXM may or may not suppress coughing relative to placebo - the study cited here appears to be have been written entirely by authors from drug companies, so perhaps there is some bias. Here's a meta analysis that favors honey over DXM https://pubmed.ncbi.nlm.nih.gov/32817011/, the original study that kicked off this idea that also favors honey https://pubmed.ncbi.nlm.nih.gov/18056558/, and a different meta analysis https://pmc.ncbi.nlm.nih.gov/articles/PMC6513626/ which found little or no difference between honey and DXM. Whether its effective or not, to me there doesn't seem to be compelling evidence that it is more effective than honey.

It's funny that TFA seems to use the comparison to honey as disparagement, rather than interpret the same information as an endorsement of the helpfulness of honey.