I use my machine as a “I need it now” back up to outsourced fabrication on industrial, and much more capable machines. I work with just about everything but wood, aluminum, composites, plastics ect.
Your concerns are not unfounded, the engraving bits, being brittle carbide, are very fragile. In fact, yours might be broken, which can cause similar effects to what your picture shows. I went for nearly a year without breaking one, and then I went through a few hundred dollars worth in a matter of a week. I have a microscope to inspect the tools, the breakage can sometimes be hard to identify otherwise. The cut result, or a small speck of carbide, is often the first indicator.
I use Onsrud tooling, and tend to stick with tooling companies that sell to, and are used by professional shops. But any quality tool manufacturer will provide essentially the same thing in this department. I haven’t used anything from tools today except corner radius endmills, they seem to be priced high, and seemingly put a lot of market energy to the desktop type user. I expect the Endmill you are using is perfectly good, and the pricing seems comparable to my tooling. Nothing wrong with it.