So many of the YouTuber reviews of iPadOS 26 are 'wow, I didn't know these iPad apps had all of these features' upon seeing the menu bar.

Just enforces the point: a menu bar is an educational tool with discoverability built in, just as much as anything else.

I have very strong feelings about this, and it's why I think the menu bar should always be visible in iPad windowing mode

Apple have made a point, too, about fitting the menu bar into the status bar area on the iPad, which is just empty space traditionally. There's no reason for it not to remain visible at all times, and hide in fullscreen mode (like on the Mac)
@stroughtonsmith What’s your opinion on menu bar alignment on iPad? Center or left align?
@markv center is inferior to the left in pretty much every way, so I'd put it on the left