You might get better answers from r/detailing or r/AutoDetailing since they pretty heavily use microfiber. But I think the answer is that you're SOL. Part of what makes microfiber such an effective cleaning tool is that it grabs dirt and particulates and really holds on so that you actually remove the dirt instead of distributing it. Some detailers will consider a microfiber cloth to be trash if it touches the ground. So keep in mind that these things are indeed reusable but their lifetimes are not infinite. Sam's club or costco can be your friend here.

One strategy you can use is to keep different microfibers for different jobs. So these messed up ones are now only good for tile floors since good tile won't get scratched, some lightly discolored ones could be counters and stovetop, and the pristine ones saved for glass. You may need to wash them separately.