Well, DRAM-less SDDs DO suck. My L5 Lite 3D NAND has DRAM cache and SLC caching, and the L3 Dark or whatever it was called was MLC (so no need for SLC caching), and I think probably DRAM cache too.
Part of the reality of today's NAND mfgs though, too, is that they are producing higher-density dies, so to make smaller (128GB-class) SSDs affordable, they don't put as many dies in the SSD to fill the channels on the controller chip as they should, to achieve proper parallelism (== performance). So yes, I agree, a cheap DRAM-less 128GB SSD is basically little more than a fancy thumb drive, albeit one with a better warranty and better wear-leveling.
But that kind of falls under caveat emptor and all of that too, because it has been known since the beginning of SSDs, that the smallest SSDs out of a family perform worse than the larger capacity ones of the same model family, and oftentimes, the benchmarks claimed for the drives, are of the largest drive of that model family, and then they just plaster those benchmarks on all of the drives of that family on down. (Granted, many mfgs these days do better, and quote benchmarks and TBW individually for each drive model. At least, Team Group's specs for their newest GX1 and GX2 drives do.)
Edit: One of the really well-performing SSDs of a smaller capacity that I've tried, are the original batches (32L 3D NAND Gen1 Intel / Micron NAND) of the Adata SU800 Ultimate. I still have a stockpile of those, and as long as you don't exceed their SLC cache size during sequential writing, they maintain excellent performance for a 128GB-class SSD.
Edit: Oh, I see that you've linked the 128GB SU800 Ultimate as an example of a 128GB-class "performance" drive. I wholeheartedly agree. They are very speedy for their capacity. $26 ea. is a steal, I paid like $45 a few years back for mine, on sale.
The PNY CS900 and Crucial BX500 128GB-class SSDs are both supposedly DRAM-less, but at least in terms of new-out-of-box performance, they both perform very well for doing the initial Windows 10 installation.
Too bad that the PNY CS900 goes on sale so infrequently. If I could get it regularly for $20, that would be my go-to DRAM-less drive, with the BX500 a close second. I'm less familiar with their longer-term steady-state performance.
Edit: That all said, because prices have gotten so low lately, I don't really even use 128GB-class SSDs, except in the most extreme budget builds. I generally use 256GB-class, and sometimes 512GB-class SSDs, for a mid-range gaming-type build, or on a laptop or NUC/STX system.