Before Christopher Colombus set foot in the Americas, did every single Amerindian automatically go to hell because no one could baptize them?
That doesn't seem reasonable to me.
Your question just ignores the numerous miracles that we know about, wherein saints bi-located to the indians and taught them the Faith. And that's the miracles we KNOW about. How many saints/priests bi-located and baptized certain indian tribes? We'll know in heaven. We don't know now. Doesn't mean it didn't happen.
The main error of many (not all) BOD arguments is reducing baptism to some type of metric, which can be measured. In other words, people act like materialists...Well, I can't "SEE" where God is helping these pagans, therefore BOD must be the answer. Well, it's not your job to "see" everything God is doing, nor could you even comprehend His workings. God doesn't need you to "understand" how salvation works. It's the height of pride to think it's even possible.