Outside of the software you need not being available in a 32-bit version, how big a problem this really is? The biggest limitation of 32-bit systems is the amount of available RAM. It is, however, possible to get around it (PAE, AWE). Clearly, they're not limited to 4 GB of memory. And of course, if you actually need to calculate with large numbers, it's going to be slower without appropriate instructions and registers. But how relevant is that to common users? We're talking about portable devices, not servers. So, I'm assuming we're mainly talking about software not being available rather than 32-bit actually being limiting.

minor thing, but you mean 'not least of which' (in the article), whereas you wrote 'least of which', which is kind of the opposite of what you mean. You need that double negative, just like 'couldn't care less' (drives me crazy when people say 'could care less').

We get closer and closer to the original AMD64 patents expiring...

2021/2022 should be breakthrough years for practical, functional, modern  "x86_64" emulation on other platforms.

Sure, the patents are of questionable legality, but nobody wants (nor has the money and will to) challenge Intel and AMD on this (Viatech in there, too, along with the remains of Transmetta @ Nvidia - they are the 4th legal x86 license holder, as per the FTC).

They still could use the help of 64 bit Linux ;) That Microsoft Linux distribution must happens at some point...