Mac Minis don't count
Sure, they are super rich and could just buy their way into the space...but so far they are really far behind in all things AI with Siri being a punchline at this point
if anything, Apple proves that money alone isn't enough
The iPhone was their first phone, and it really kicked in the smartphone race into high gear. Same for the Apple Silicon processor. And those are just two relatively recent examples.
So both are not very good examples, because they build up experience over long periods.
They are examples of something they could similarly do for the Apple Neural Engine but in a bigger scale in the future. They have experience deploying it in a smaller scale/different versions, they would just have to apply it in bigger scale in order to be able to compete with NVIDIA.
Also, while Apple did create their first chip (at least of their current families) in 2007, they did acquire 150 or so engineers when they bought PA Semi in 2008. So, that gave them a leg up compared to building a chip team completely from scratch.