Unironically, yes. They can't be doing everything all at once when it takes their full power to even force topics to be discussed on the senate floor and write proposals. Every second that Bernie Sanders talks about weed, for example, would stop him from putting up pictures of Palestinian children begging for water.

If a state has zero laws about cannabis federal schedule makes it illegal

And many of the states that haven't legalized use the federal schedule as rational.to not legalize.

If they want them illegal, they can pass a law making them illegal. That's how it's supposed to be work.

Not states having to legalize something on a state level because the federal government claims it's one of the most dangerous drugs in the country, but won't actually enforce people flagrantly breaking the law...

Have you ever tried reading anything about this? Like, ever?