I don’t print any abrasive materials at all. Pretty much only normal PLA and PETG.
I noticed, that my print quality gradually went down quite a bit, especially in the last few prints. I had a lot of stringing, weird blobs, and scarred surfaces.
Now, the print quality is as good as it should be!
They are dirt cheap. You can get a set of 10-15 generic ones, in different sizes, for only a few bucks. Don’t forget that they are consumables.
Changing nozzles is important as they are consumables, but all of your high quality close up shots are showing a practically unscathed nozzle under a lot of gunk (the picture of the back end of the nozzle has a big chunk of cooked plastic that will pretty easily scrape off), if you cleaned it you’d probably be just as well off as with the new nozzle
The larger photo shows a lot of wear on the end compared to the new nozzle (the flat area on the top is larger). It’s hard to tell from the photos but in my experience this generally correlates to a widened nozzle diameter and decreased print quality.