Microsoft uses apis(like DirectStorage) to help mitigate(but not eliminate) certain I/O bottlenecks. But the thing is, an api acts as an interface (a middle man) between the hardware and the OS(plus it's applications) and there's only so much you could do with an api before you eventually hit a brick wall and are unable to move forward. Microsoft can bring the world's forefront algorithm experts and software engineers and even after writing tens of thousands of lines of code, they still wouldn't be able to do what dedicated hardware(like the I/O block) can do on its own.
That's like telling me that if you take an RTX 2080TI and reprogram it to perform only matrix operations and complex floating point operations to do cryptocurrency mining exclusively it would be able to have the same speed and efficiency in mining as a dedicated ASIC(application specific integrated circuit) like the antminer S9 which was purpose built for that specific workload, it doesn't really work that way, at all. Microsoft made a big fuzz about their ssd until Sony broke their silence and ever since it has turned into nothing more than a d!¢k measuring contest where one goes "hey i have this piece of hardware that was purpose built for that job and the other goes, but mine is also pretty fast).
If Microsoft wants to convince gamers that the Xbox series X is using more than just fancy buzzwords for its hardware, then they'll have to stop taking fancy terms and slamming imaginary multipliers (like the 2-3x multiplier of sfs) next to them that to me sounds like tales from the corporate butthole and borders on astroturfing. The series X has a decompression block, that's it. That decompression block is, according to Microsoft, capable of handling more than 6GB/s at its peak. That 6GB/s is where you draw the line, it's your bottleneck and your inherent limit and no matter how hard you code, you won't be able to bypass and circumvent that limit no matter how much black magic you use.
So, no, SFS won't give you 9.6 or 14.4GB/s when you utilise it because you'll then be going over the limit of the decompression block and you just can't do that, some people think that Microsoft managed to do what sony did with the I/O block, by countering it with software and APIs that according to tales from a fanboy's ass can defy the laws of physics and engineering when that couldn't be any further from the truth. You can't get with software what dedicated specialised hardware gives you and that's a fact and you certainly can't emulate lanes and priority levels through software no matter how hard you try. If Microsoft wants attention, stop with the fancy buzzwords and show the games, only then will they convince people and do what fancy terms could absolutely never do.
Remark(May 25th 2020): Made some slight changes by splitting the post into 4 sections to make it easier to read.
