This is a motte-and-bailey fallacy that got brought up a lot by gambling proponents early on. The biggest difference is that by design investments on average will return a zero or net positive potential for return. Gambling will always return an average negative return by design.
EDIT:
There was a study that came out a month ago that showed that state by state when online sports betting became legal, there was about a $20/month reduction in retirement investments. Considering only ~12-20% of the population has taken part in sports betting, this is not an insignificant reduction in retirement investments.