The only "crapware" I'm aware of is CPURocket, which I don't actually remember - I think it was a freeware product that the company produced that adjusted the priority of the foreground window for better response at the cost of background apps. So wherever your mouse focus went, it would find that process and bump the priority temporarily while it had input focus. It was free, and Gator licensed it to use it as a "lure" for their advertising platform. In retrospect, being involved with ANY of the ad networks from circa Y2K isn't the best choice I ever made, and I do regret that... but it was "how things got done in 2002," I guess.
HyperCache, Memturbo, ClipTrakker, etc, were all good apps that I wrote the initial versions of for myself.
After all, you had 30 days to try them out before buying, fully functional. And then another 30 days for a full refund if you changed your mind. And 800 number toll free support, too.
Even Registry Cleaner was real - though I didn't write it - and was inspired by Microsoft's own Registry Cleaner. It would do the basics of cleaning up dead entries to non-existent DLLs, registry sections, and so on. It would also repair registry entries that were required for booting, like the shell= line of explorer, so if your default shell got broken, it could fix that and so on. At the end of the day it was just a registry cleaner, but debloating the registry isn't a terrible idea. How much value is in it varies by user, how old the machine and OS is, etc. To be completely candid, I used to run it all the time, but haven't bothered in the last 10-15 years, as everything is "fast enough" these days.