I think by the time I want to upgrade my memory, I’m almost certainly going to want to upgrade my processor. And with the Framework specifically, it’ll be far easier to just upgrade the whole logic board than any other laptop with upgradable memory.
Change my view.
Kind of hard to change your view on what your needs are, it’s totally up to personal preference. I haven’t needed to do any hardware upgrades on mine yet, but in the past, I did have to upgrade my desktop’s RAM because my computing needs changed. When I started learning 3D modelling, I found my computer was having a hard time and memory usage was topped out. I didn’t need another processor, SSD, GPU, or anything; I just slapped in 2 new sticks of RAM and that smoothed it all out.
To save money, I’m going to forego buying 32G of DDR4 3200 for now, and instead swap in the memory from my old not-as-repairable laptop. Then, whenever I feel like upgrading, I’ll drop $150-300 on 32 or 64 GB of fresh, spicy memory.
That is, if it POSTs with the RAM I’ve got, of course 
The use cases for my devices evolve over time. Five years ago I wasn’t running VMs for much of anything. Now, I have a VM server with over a dozen VMs running on it.
I bought 16GB for my current model, which is sufficient for how I use the hardware today. But I might discover, five years from now, that I need 32GB or 64GB, because my use cases have changed.
And that’s ignoring the second-hand market, where someone might buy a lower end model and upgrade components.
It’s not just about upgrades. I’ve had memory fail before, which caused data integrity issues. Replacing it fixed the issue.
Furthermore, it lets the consumer choose configuration. When I was looking for a laptop, I was having a difficult time finding one with my memory wants that want super expensive, and came with a bunch of things I didn’t want or need.
Upgrades also help repurpose hardware. You may not use your old board in a laptop after upgrading. Maybe it will be a home server, or a “all-in-one” for an older relative, or w/e by purchasing cheap used RAM. Old processors can still be very useful, but running out of free RAM massively slows old hardware down, because when you need it, you really need it.
Repairability. If your memory fails, but everything else is good, it is easy to swap out. If something else on your mainboard fails, you can keep the memory. No matter how you slice it, more modularity means less waste when things fail.
I think this is key from a low-waste perspective too. If each laptop can be modified slightly as needed, they will have a longer total lifespan once one considers resale and other repurposing. Maybe you don’t need 32GB of RAM now, but maybe your laptop will find a second life as a home server running a bunch of services as VMs. Certainly better than sitting in an e-waste center, pretending to be recycled.
It’s one of the reason Apple decide to combine RAM onto their CPU/GPU altogether, seeing not as a independent part but rather together with CPU (and GPU).
And it’s not a terrible thought.
HOWEVER,
When you purchase a top-of-the-line processor, especially from Intel since they last longer, you can be using the chip for 3, 5, 7 or more years, during which memory requirement for tasks keep increasing. As such, instead of purchasing a brand new board (or device altogether), you buy some RAM for the upgrade.
It’s like the argument “yeah, stuff in cars break. So why bother replacing, say, the spark plugs when you can just replace the engine since the bore and piston rings wear out and why just not get a new car altogether”
But the cost of replacing a engine or a car is much greater than replacing spark plugs or reconfigure the ecu.
It’s also worth noting that modern devices are surprisingly capable – for example, I had played World of Tanks on a Intel Pentium 6405U. The only reason the platform will work is because I upgraded the RAM from 4GB to 16GB – something you can’t do when the RAM is soldered.
It’s about “future-proofing” the device – when I purchased the Dell XPS 9360, I thought 8GB of RAM is enough. One and a half year later, that was completely not the case. And the sad fact, is that the chip is immensely capable – it’s a i7-8550U. But I can’t use it to the full potential. This Pentium, however, I can. Because I give it the RAM to multitask.
Heck, I can probably crank to half res assets for KSP and keep it going, unlike on 9360 where I have to keep it quarter or eighth.
On the other hand, desktop motherboards and CPU sockets are less the case – since by the time you need to upgrade, new CPUs with new features (which require new motherboards) have likely arrived, thus there is not a lot of reason to keep those two independent. Unless you can swap out the different generations of CPUs, which is a plus in any way.
However, there are cases where physical failure to motherboards can happen, and this is when a detachable CPU can come in handy. Compared to DIMMs, however, it is quite less important.