Well it means nobody can avoid their extortionate upgrade pricing anymore so I think that decision paid off well for them.
The first thing I used to do when getting a Mac Mini was ripping out the memory and sticking in the max I could get. For a fraction of Apple's price. Some of them even had more memory than Apple offered itself.
I know there are also benefits to the soldered memory like the huge bandwidth but still. That matters mainly for very specific workloads like LLM inference.
I remember when they basically bought up all of TSMCs capacity for a year.