Simple reasons:

- The cloth masks don't form a tight seal and leave two gaping holes on either side of my nose.

- The cloth masks don't have as fine a filter mesh and aren't as effective at filtering tiny particles.

That said, I don't go out that often, and my trips are limited in time, so I reuse a disposable N95/KN95 mask until I've worn it for as much as a total of 30-100 hours before I dispose of it. I also use reusable everything else wherever I can in my life, I just haven't found any actually good reusable masks that would pass e.g. NIOSH tests.