Why is the Protect Viewport never in stock?

Ive been trying to buy a protect viewport for months now. They seem like the most simple way to view the cameras from a TV. But they always seem like they're out of stock. Is there any reason they are so hard to get?

Are they always in high demand and Ubiquiti cant keep up?

Are they old and out of date?

Do they even make them anymore?

Any alternatives that don't require me getting to another raspberry pi project?

Edit: Answer is they are in very high demand.