All this hype about internal read speeds is starting to sound more and more like an excuse to limit storage expansion options again. This is starting to feel a bit like 7th generation 2: Electric Boogaloo.
What an odd conspiracy to ascribe yourself to. There is no way that someone is sitting at Sony cackling to themselves that they have thwarted Souffrir and his dreams of expandable storage options for PS5.
Yes, unfortunately it took till 2017 for external usb to be an option on PS4 (we can argue that it took too long). However as someone that has played hundreds of PS4 games, and has only had ≤50mbs internet for most of that time, it never was some huge issue for me. I can't play 10+ games at the same time, so, I have honestly never even used an external drive on my OG PS4 (or my Pro). I did however upgrade the internal HDD (500gb to 1TB), about 2 years before upgrading to PS4 Pro (super easy to swap).
This is 100% all about moving forward from old disk based hard drive systems and to a newer much more beneficial SSD. Unfortunately that does come at a price, both fiscally and physically as at launch you will be limited with options to expand. But it's absolutely going to be hands down the BIGGEST and most significant change with PS4 to PS5 anyway.
Without the SSD you are looking at a new console that wouldn't function much differently speed/loading wise, and still won't look much different graphically from PS4 Pro for likely 12-18 months when the "real" PS5 games start launching.
SSD benefits however are immediate and long lasting.
Sure it sucks there isn't more storage at launch, and sure it sucks that USB storage only works for PS4 games, but this is a price worth paying for the long term relevance of the console. SSD prices will come down and storage options will be there, but if you would rather they stayed with a disk based hard drive with 2TB or whatever at launch, then the PS5 might as well not even release for a few more years till the costs go down. And we certainly could argue that as well. But I think most people are ready to see a new "gen" of hardware at this point.
My personal PC has had an SSD for as long as the PS4 has been around. So the idea of launching a console in 2020 without one is ridiculous, and the fact Sony wants to go with a "cutting edge" newer type is once again, only good news for the long term life of the console.
But no, there isn't a storage conspiracy here. It's not like Sony held anyone hostage with not being able to upgrade OG PS4's with larger internal HHD's. They didn't sell proprietary PS4 internal drive upgrades either. If you really need all that storage day one, I have to break the news to you, there won't be all that much to play anyway.