The slippery slope is a fallacy only because there’s no proof things will go one way or the other. You can use slippery slope to say ridiculous things. E.g “if we let gays marry, it’ll be pedos next” is a good example of the fallacy whereas “if we let private corporations spy on us for a good reason, they’ll expand their powers to extract even more profit” is not, but either way, you need to know the context (which is that corporations serve to extract maximum possible wealth and have no morals).
The slippery slope is a fallacy only because there’s no proof things will go one way or the other. You can use slippery slope to say ridiculous things. E.g “if we let gays marry, it’ll be pedos next” is a good example of the fallacy whereas “if we let private corporations spy on us for a good reason, they’ll expand their powers to extract even more profit” is not, but either way, you need to know the context (which is that corporations serve to extract maximum possible wealth and have no morals).