You're misremembering. The Macbook Pro M1 (2020) supported a maximum of 16GB, and the base Mx chips have never been offered in a 64GB configuration.
And they invariably point out where the official Apple specs fall short of real-world options, such as the RAM limit of the 2018 Mac Mini -- officially Apple says it’s 32Gb (and for the longest time even sites like Crucial.com offered only 2×16Gb sets for that model), but MacTracker very quickly pointed out that it can take 64Gb. IIRC this was right after iFixit did their teardown and realized that the CPU did not have a 32Gb memory limitation, and successfully booted that model with 64Gb.
Now, from what I understand the M1 only allowed 16Gb as the max addressable memory - I dimly remember a video where someone tried to resolder with 32Gb of performance-identical chips that had twice the capacity, and it could still only see 16Gb of it - so it appears to be a hard limit either in the memory controller or as a direct feature of the CPU cores themselves.
There is no duopoly or monopoly in the laptop market. Apple computers are not "must-haves," and there are many cheaper alternatives. They are high-priced products—closer to luxury goods than essentials. Ultimately products are priced based on demand (what people are willing to pay) rather than just their production costs.
DDR5-6000 2x32GB prices have increased five fold. https://de.pcpartpicker.com/trends/price/memory/
AI clouds are eating all RAM available and increasing prices.
There are no laptops with performance and battery life that come close. No fans needed either (Mac air)