State Assemblyman Robert Carroll is pushing a $3 tax on package deliveries as a jab at Amazon’s power. Yet it would mean big trouble for lots of other businesses, too.

Yes, the Park Slope Democrat would exempt food and “essential medical supplies” — but lots of other companies are now looking to deliver, and few can afford to swallow the fee as Amazon might. Plus, countless small businesses rely on receiving daily deliveries.

Indeed, as one local tweeted at Carroll: “I’m a small biz owner trying to stay afloat in NYC & your proposed tax would hurt me WAY b4 Amazon feels even a pinch.”

Nor is it only the “rich” getting deliveries these days — and just a few of those $3 fees would hit low-income New Yorkers pretty hard.

Carroll’s claiming his plan would bring at least $1 billion a year for the MTA. But he’s been pitching it since long before the “existential crisis” he’s now pointing to. The transit agency may well need new dedicated revenues — but not this one.