We don't know if Gaterons are more reliable than genuine Cherry MX - and since they produce the Zealios, they will fall under that general statement.
The general impression given is they are unable to adhere to the same strict tolerances in their manufacturing process - this makes sense, as ultimately the Gateron specific switches are an attempt to provide a cheaper product alternative. It does seem that their community engagement and willingness to make tweaked products (Zealios!) sets them above their peers (Kailh, Greetech, etc).
An assumption behind your argument, that is not necessarily true, is that lower cost equals lower quality, which in contemporary manufacturing systems is just not true.
Especially now that Cherry switches are 20+ years old, I can't imagine that making a cheaper alternative would be that hard to do while maintaining or even surpassing the quality of the original.
There are certainly cases which lead credence to what both of you are indicating, however, with respect to Gateron, we know of switch chatter and switch wobble both being issues.
When specifically referring to Zealios, measures have been taken to reduce chatter, but Zeal has mentioned that convincing Gateron on tighter tolerances is still a a challenge to be overcome for R3.
This still does not address general reliability over a long period of time. If anyone has seen published figures with respect to MTBF or even before "out of spec" figures along with supporting evidence on how these figures were achieved, I'll gladly read them.
Regardless of how my cautious attitude above may be perceived, I do believe it a good thing clones may have the potential to force Cherry's hand, lest an option like Gateron continue to improve to the point of clearly asserting itself superiour.