Earlier quoted context omitted.
I think it's more because of the PCIe interface, and access control and encryption through the T2 chip. The PCIe interfaces SSDs that Apple's been using allow really fast speeds of upto 3Gbps, which is almost double those offered by other interfaces like M2 or even more faster than SATA. What's disappointing is the base storage. 128GB in 2019 is so ridiculous. I would't otherwise mind a soldered SSD when I can just u…
The two I installed this week are using 70GB and 90GB all set up for development with my files. I think there are plenty of people who needn’t spend on an extra 128GB. Especially since the USB ports are plenty fast for bulk, non speed critical storage should you decide to archive something locally.
You can run MacOS or Windows on 256 GB almost indefinitely, even as they grow it would be five or more years before it becomes a headache, to keep 128 GB happy you have to babysit/rebuild semi-regularly.
I'm yet to see an OS which doesn't bloat as it ages, even on mobile devices. 30 GB free won't be 30 GB the next major OS update, including rollback files, logs, and so on. OS bloat is also one of the few things you cannot offload to external storage.
And I'm someone that ran off of a 128 GB SSD for almost two years.
PS - Plus increased resale value will likely pay for itself.