[adolph]

Yes, it was clear during the post epidemic chip shortage their primary customers were companies embedding it in various ways [0]. This has enabled them to execute on what I think is an excellent vision with the Pi Pico (including using it as a peripheral bridge on the 5).

At the same time, the B model and the 500 are oriented toward a general purpose tinkerer audience and RPi even highlights PCIe on the 5's homepage as if M.2 was natively on the board instead of a FPC connector (there is a caveat further down the page).

I appreciate RPi's vision and long lead times and think it would be interesting to hear the story of how they came to the decision of FPC plus power from 40 pin as opposed to building out M.2 (which could also be used for wireless, NPU/TPU, OCuLink, etc). Maybe it had to do with what they thought they could support with that Pico peripheral interconnect? Unlike standard PC makers they aren't taking a batteries included mobo chipset.

  All aboard the PCI express
  This addition to Raspberry Pi allows you to connect an M.2 SSD to your Raspberry Pi, giving you speedy data transfer and super-fast boot.

0. https://www.pcmag.com/news/shortages-prompt-raspberry-pi-to-...

1. https://www.raspberrypi.com/products/raspberry-pi-5/

[teamonkey]

It honestly is weird that the 500 doesn't have a M.2 slot, being an all-in-one package. Not all of the Pi's use cases would benefit from fast mass storage and so you can understand why they wouldn't add a M.2 slot as standard if it keeps the BoM low and board size small. Not so with the 500.