I’ve been using 7075 charging handles professionally for two decades. I’ve never broken one, nor can I recall seeing one broken. I know it happens, but it is uncommon.
Jerry Mickulek’s job is to sell things. His sponsors view his freakish ability to shoot as credibility for endorsements and advertising. Even if he’s actually breaking charging handles, almost no one, including Delta Operators, shoots as much as him, and competition has a unique requirement to manipulate the charging handle at a greater frequency than other forms of shooting, due to “lock and show clear” concluding every stage. Something like 20 times a match day, plus however much is done in practice, dry fire, and while clearing stoppages.
A steel charging handle is completely unnecessary. You are never going to wear out or break a 7075 ch. In my 20 years of using the M16/M4 platform in the military and civilian sides I’ve seen 1 broken charging handle and that was by two Marines with a steel cleaning rod and a hammer(I may or may not have been involved)in which case that was the best outcome for it to fail saving the rest of the upper.