There is strong suspicion artificial sweeteners mess up your gut biome, but it’s not yet as established as the evils of sugar.
Also, I think there might actually be some links to type II diabetes, but I'm skeptical of causation on that one. It's not implausible, but fully correcting for people already trying to reduce sugar intake sounds essentially impossible in that case.
A search on Google Scholar shows multiple publications exploring the adverse effects on sweeteners on gut microbiome:
https://scholar.google.com/scholar?q=artificial+sweeteners+e...