Review Seagate FireCuda 510 M.2 NVMe SSD Review: One Expensive Fish

I don't see how that would count against it. Next-gen controllers haven't dropped yet. Most of the market is Gen3 based. Intel doesn't even support the Gen4 interface yet, either.
The lowliest of current generation of Ryzen 3k chips do though, such as the Ryzen 3300X @ $120.00 USD, which supports Gen 4 on the B550 motherboards, starting @ $89.00.
 
The lowliest of current generation of Ryzen 3k chips do though, such as the Ryzen 3300X @ $120.00 USD, which supports Gen 4 on the B550 motherboards, starting @ $89.00.
Yep, but if someone is buying low-end hardware, to begin with, they aren't going to splurge for Gen4 SSDs that cost a premium for very little advantage.