The Galaxy Tab S9 Ultra aims to bring two worlds together: work and leisure. In our test, the Galaxy Tablet reveals some strengths for gaming and multimedia use and is also able to perform convincingly in the productivity area together with its S Pen. But this also has its price ... https://www.notebookcheck.net/Samsung-Galaxy-Tab-S9-Ultra-review-Excellent-tablet-with-wow-factor-remedies-a-weakness.754093.0.html
Windows or ChromeOS would make much better sense for this kind of tablet, even with ARM SoC. Samsung already has the hardware to create a compelling Surface Pro competitor. Android still doesn't have enough capability to be a proper desktop OS.
I'd argue the opposite: this is a mobile device, and Windows or ChromeOS are not good mobile experiences. For example, the ARM Surface Pro 9 ran hot under load and got less battery life than similar Android devices (www.notebookcheck.net/Microsoft-Surface-Pro-9-ARM-review-The-high-end-ARM-convertible-disappoints.699137.0.html).
As for using it as a desktop, I currently drive a 4k display and full desktop keyboard with a Samsung S20 FE using DeX and their Good Lock app, including building large C++ codebases like LLVM in the Termux app. For me, it is a better desktop OS than Win/CrOS, though there is always room for improvement.
Even more expensive that Apple's obscenely priced iPad, for half the performance. LOL
Apple has become a luxury company.
Samsung is just a tech company making ok products, someone should tell them they're just not playing at the same level.