Because most people conflate "buying a more powerful computer" with "future proofing", which is wrong.
I future proofed when I built my desktop in 2017. We knew am4 was going to be supported for several more cpu architectural generations, so I knew that I'd have an easy upgrade path ahead of me, for cheap. And I did. I went from a 1600x to a 5700x, and from an rx 480 to an rx 6700xt. I fully intend to get another couple years out of this pc, and it's looking like I'll be able to get possibly a full decade of useful life out of it. That's future proofing, and pretty cost effective.
On the other hand, had I bought the best available at the time, which was Intel 8th Gen coffee lake, it would feel so much more outdated and I'd already be in need of another upgrade.
In any case, I'm not sure there's any such thing as a future proofed MacBook. Aren't they pretty limited in terms of upgrade options?
They last a long time because the build quality has been excellent, historically, and also because 99% of the user base never runs an application heavier than a web browser. But then, my decade old windows laptop is also fine for web browsing.
not really clear what you're asking for, to be honest.
So it doesn't matter per se whether it's a 4g router, other than the fact that a lot of those services won't give you a publicly routable IP. Is this device a windows or Mac device? You can use things like Chrome remote desktop to completely obviate the need for anything particularly fancy.