Exactly!
Example:
https://www.amazon.com/Natural-Sweetener-Erythritol-Sugar-Fr...
Look at the list of ingredients.
An anonymous powdered chemical in a plastic bag. Hopefully not imported drop shipped via Amazon from China by the same people that import the phone chargers that catch fire and the fake microSD cards...
Top 5 hits on Amazon for "monk fruit sweetener" all have Erythritol. Some mention it in the product name, some later on in description, etc. Have to read very carefully.