Is it? Thanks to the increased reliability that non-upgradeability confers I'm still using my 2012 MacBook Pro as my daily driver. I suspect there's a lot of minutia to tease out to verify whether this claim is actually true in the global case.
For that reason, I don't see why you would expect to upgrade your laptop. I currently use a home-built workstation and rarely upgrade it. By the time the CPU is outdated and tired, you also want to swap the GPU. My 128GB of DDR4 is useless in the world of DDR5. So it's not like I get a ton of upgradeability by having a workstation. I can keep the case and the fans for the next build, saving me $150. Woo. (I have kept my NVMe SSDs forever, though. But they are inexpensive and "rsync" after the upgrade is not too onerous, so it's pretty reasonable. But, technology improves there too. I have PCIe-4, but my SSDs don't take advantage of it. So keeping them just gives me slower storage.)
The only thing you have to be careful about is sticker shock vs. future needs. Upgrade is pay later, but laptops are pay now. It hurts to price NVMe SSDs on Newegg and then pay Apple $2000 for it. That might be what people are talking about with "upgradeability"; "Apple is too expensive".
I'm skeptical of those being connected; my 2008 thinkpads and 2011 desktop (that I'm writing this on) are extremely upgradable and still work fine (I mean, the thinkpads are slow by modern standards, but that's not a reliability issue). And non-upgradeability in this sense also means that it's not reparable either, so when it does have problems the whole thing is dead rather than, say, just swapping out a faulty RAM module or replacing the worn-out SSD or whatever - to say nothing of the battery degrading.
> I wanted a cheap travel laptop I could replace without blinking an eye at the price.
It's pretty easy to get ~10 years out of a good laptop from Apple. I'll be shocked if this guy is still using his Thinkpad in 10 years, and even if he does, that he didn't create more e-waste by swapping parts that he wouldn't have had to sticking with the MacBook.