OLED already works very well for TVs and other big screens; MicroLED would need to push into that market and prove its value against OLED. And OLED tech will not stand still while MicroLED catches up.
MicroLED needs market niches with lots of manufacturing volume to scale up and improve or they'll never get to a position where they can challenge OLED.
Google only pays because Firefox has enough users to justify it. If enough users switch to Chrome because of broken Google-owned websites, why would they keep paying?
"There's always one" is a common rhetorical device whose meaning is closer to "There's often one, and I easily forget the times there's not." I don't think the parent's intention was to make such a claim.