If there are many apps opened, you can slide the navigation bar horizontally to access them.
So what exactly is the benefit of that compared to what we have now, where we also scroll the cards?
If it's about how many cards you see on screen at once, then why not make the cards smaller? On large screens, we might also add a second or third row of cards. so we'd be able to see 2x2 or 2x3 card at any one time in the task switcher, including their images, rather than just the app icon. I'm just thinking out loud here and wondering why your approach is better? At least from where I stand I think an objective argument can be made that it is not (because you only get the app icon rather than the image and you'll still end up scrolling), but maybe I'm missing something...
The Taskbar Experience can be turned on or off by the user. If you dont like it, simply dont use it.
Which is how all the last 2000 bad concepts were justified. If this was the typical approach to this sort of thing, OSes would be filled to the brim with bad ideas that we'd be "free" to turn off. The thing is, every feature, even after the initial version is released, continues to drain money and developer time to maintain it. For these reasons, every idea must be good, and unfortunately, even many of those ideas that look good on paper don't end up being good in practice. I don't think yours even looks good on paper... at least not yet.
I'm sorry for being a pain in the rear. I know a lot of enthusiasm and effort goes into making these concepts. It's not easy, and I applaud your great attitude towards criticism. If you can keep that up you'll go places ;-)
As it is now, I think I gave reasoned arguments for why this isn't a good idea. I think you need to come up with a better counter argument than "well, you could turn it off".
Either way, wish you all the best.