USB 3.0 is 5 Gbps, which is pretty much the limit of SATA SSDs anyway (6 Gbps is not that much farther than 5). Realistically, I have seen speeds up to 500 MBps on SATA SSDs over USB 3.0. This is plenty fast even for games and such as well.
The real benefit of SSDs is the instantaneous seek. Real world work loads, even games, don't have single file of multiple GBs, they have many many small files. That's where the instantaneous seek comes in handy.
People routinely overstate the importance of fast transfer rates. That helps, but don't underestimate how fast 5 GBps is. Unless you routinely deal with multi-GB files, you're never going to notice any difference between a SATA SSD and an NVMe SSD.