What you should be comparing Hyperloop to is airplanes, not other land-based transport systems. Hyperloop is very fast, and is meant to compete with regional air travel. It's not likely to be cheap per-ticket, so it's not comparable to trains and cars. It's not meant to move large volumes of people cheaply, it's meant to move high fare-paying people very quickly so they don't have to deal with the problems inherent in air travel.
You are now making lots of assumptions for each mode of transport without stating them.
Given that none of the companies working on different Hyperloop concepts are even directly replicating the original proposal, your assumptions for hyperloop may or may not hold, but without stating which of revised models you're discussing throwing out numbers like this is entirely meaningless.
In contrast, a regular commuter train can carry ~1000 people per train, and you need to dispatch them at 3 minute intervals (20 trains/hour) to move 20,000 people per hour. A single lane of road traffic will carry ~2000 cars per hour. Assuming single-occupant vehicles, that's ~2000 people/hour.
And that's loading them at the lazy pace of a tourist attraction. With longer platforms, experienced commuters and more staff, you might be able to send cars out even faster.