DRAM Cost / GB hasn't been getting any cheaper. ( Not adjusted for inflation ) Unlike NAND at cost per GB, or Consumer CPU cost per core ( not a fair comparison due to die size difference but relevant in this context ), hence it is an expensive component in terms of overall system. You get higher throughput, lower energy, but not lower cost. In fact your 8GB LPDDR5 in latest MB cost more than the 8GB in 2015 MBA even adjusted for inflation.
And there are no current roadmap to suggest we could break this trend. While we could and are continuing to shrink transistors, you can only do so much with capacitor inside the DRAM. Unless we have some fundamental breakthrough, this will remain the case for DRAM in the foreseeable future.
I still remember I was called out and attacked for suggesting this in ~2012. That machines in 2020s will remain at 8GB.
Apple and other manufacturers thus had to keep 8GiB models around so they had something to boost to entice you to the more powerful models.
So a few professional laptops went with DDR4 as LPDDR4 support floundered for years, but most stuck to LPDDR3 as most consumers would notice an extra 30 minutes of battery life on the spec sheet more than RAM they wouldn't actually use.
It's only with Ice Lake (low quantities) and Alder Lake (more available) on the Intel side, M1 on the Apple side, and Ryzen 4000 on the AMD side that it's as cheap (cost and battery life) to have a system capable of more memory.
But plenty of consumers still haven't complained about their 8GiB systems, so they still sell them.
I'm currently typing this on a 2008 MacBook Pro with a 2.5GHZ Core 2 Duo and 6GB RAM. It's playing a 1080P video on a second monitor and has 5 browser tabs open in two browsers. Currently using 4.7GB RAM and 60% CPU.
That being said, the lowest config is often something that is just there to meet a price point for advertising purposes, not what Apple actually expects people to buy. They've been doing this for decades. 16gb was the "standard" in 2015 already for most machines.
1995: 4 Mb of memory was $129
2002: 256 Mb of memory was $34.19
For those who weren't around, the progress in both memory and CPU terms during the 90's was astonishing. Order of magnitude improvements every 2 years. We have nothing like that rate of progress now.
Still, 8GB is simply not enough for anything close to "pro" needs.
Why not increase the potential pool of buyers with specs that are acceptable to them?
Also, M1 Architecture over Intel taps into solid state storage speeds to aggressively use swap storage when mem pressure exists. It really seems to be smooth, I've not noticed much hiccups. You might remember folks getting upset at this a year back because of the unexpectedly high SSD wear that results.
Compression for memory on macs has probably removed a lot of this pressure to increase beyond 16gb.
For the arm solutions moving the memory on package also may be a limiting factor, since there is only so much space available.
Lastly since macs have memory fixed to the package or motherboard failure is expensive, since you’re replacing an entire system board. They have about a 1.5% afr.
However, when the supply chain is crunched (as it is now), Apple's build-to-order MacBook Pros take two months to deliver. This means that the only available models to purchase immediately from retailers are the low end models that don't cut it.
I doubt it will ever change though. There is more profit in keeping the price low for customers that don't know any better rather than accommodating business customers that need something workable immediately.
8gb is the minimum and is still working fine.
Plenty of ram for plenty of use cases.
Not everything has the same CPU to memory balance.
It is a criminal act by any manufacturer to sell a computer with 8G of memory specially when it is not upgradeable.