The slippery slope is a legitimate risk consideration as often as it’s a fallacy.

We already have laws about toilet flow rates and lighting types in the US, and other countries have more.

Sadly it isn't a fallacy at all, academic degrowthers in Europe (yes, degrowth can be studied at university in Europe!) have proposed de-incentivising the use of washing machines: https://x.com/ziontree/status/1837034922105516391

The slippery slope is only a fallacy if you assume dogmatic priors, otherwise it is simple Bayesian updating.