The iPod wasn’t a video player. Until it was.
The iPad didn’t have stylus support. Until it did.
Macs don’t support touch. Until they do.
Not only is this a non-argument, it doesn’t even mean anything since the categories are not narrowly defined.
Even if this is true, it is entirely I. R. R. E. L. E. V. A. N. T for this discussion.
Did you not even read what you quoted, in this post? A more than casual workload on macOS hovers around 5W. This is NOTHING for an iPad.
Final Cut Pro, JavaScript and GPU-intense games should all be banned from the iPad if your logic is applied consistently, and macOS shouldn’t be allowed on the MacBook Air because the Mac Pro handles heat so much more effectively.
There are zero rational technical reasons to not allow macOS on an iPad. One could argue performance, but considering Apple still sold a Mac with a spinning disk in 2021, that argument doesn’t hold up very well.