This is all part of Apple's plan to make the MacBook a perishable device. Adding the SSD to the SoC is probably the most egregious example of planned obsolescence I have ever seen. The SSD will stop working a some point due to it having a definitive lifespan and it will result in the entire system becoming eWaste.
Most people don't quite get how long electronics can last. I still have ancient computers from the 80's, such as the Macintosh 128k which is my avatar, still running despite being almost 40 years old.
It'll probably not affect basic consumers as most laptops tend to get replaced after 5-6 years and the SSD will likely have around a 10 year lifespan.