Many “revealed religions” depend on prophets and holy texts to get their messages out to people: in order to figure out what God wants, you either have to read this holy text or have a class of priests that read the text tell you what the text says.
But this is a form of cultural diffusion: whether or not the text is available to you before the modern world (with printing presses and internet) depends on whether you’re born in the region where the book is in print, whether your culture supports the priest class that can tell you what the text says (such as if you’re illiterate), things like this. Even today, we see religions based on particular texts to be somewhat geographically locked as tends to happen with things (like fashion) that are spread through cultural diffusion.
Why would gods choose such an obviously inefficient way to spread their message, especially if (in some worldviews) that message has infinite consequences?
For instance, for a being with godlike power, it would be trivially easy to just implant whatever knowledge is supposed to be gleaned by the holy text directly into every newborn: then it won’t become region locked, people wouldn’t fight over whose holy text is holiest, people wouldn’t be born in regions that don’t have easy cultural access to the holy text or priest class that reads it, etc. Why not this instead?
I'll answer from my "churchy" perspective because I think that's what you are looking for. It is really only a story not so much an answer.
In my religious upbringing, we were told there were two fundamental plans for creation. One founded by Lucifer and One founded by Elohim (The Father God). The objectives were the same: Have every spiritual formation receive a physical body and Once life was experienced, have as many of those spiritualized bodies return in a purified immortal form (gods).
Elohim's plan was as we see it today. We would start from scratch and just get scratchier as we live this life, hopefully listening to our natural compasses and making the choice to realize that we are godly spirits trapped in a mortal body and are meant for so much more.
Lucifer, known for his ingenuity and spiritual adeptness proposed something very similar to what you suggested at the end of your OP. He wanted every spiritualized body to have built within their cores knowledge and perfection. He knew the dangers of giving people their own free will and calculated the potential losses due to the inefficiencies that Elohim proposed.
Their dialogue would have went something like this:
'Why allow people to suffer, when we are fully able to fulfill your objective without any losses or suffering?" - Lucifer yelled
Elohim calmly responded, "Because in order to do that, you must take away one's ability to choose. We want to create people. Not machines"
"You want to create chaos. People are so flawed and weak. They will kill you the moment they give you a chance, and they will spit on your grave. You will only make them worse by giving them choice. Why even create them at all."
"Because I choose to. Just as you have the choice to reject my plan."
"Well I also choose to fulfill my plan whether you like it or not, We will see who will still choose your pathetic plan in the end."
"Ok child, but not under my roof. You are going to have to find another place to oppose me."
"Fine. Be it that way. I never liked this place anyways, I already have spirits who agree with me and I know a perfect place to set up. I helped build it so I don't think you would oppose."
Lucifer and his many followers took Earth as their home, receiving no flesh, yet maintaining a vast intelligence and knowledge of creational and spiritual properties in order to manipulate and recruit Elohim's followers to join their plan and reject Elohim's. Lucifer received a new name as Satan, purging himself from his own freedom of choice.
According to this story, any human of flesh and bones, had been exposed to Lucifer's plan at some time in their premortal existence (as spirits) yet chose to participate in Elohim's plan. They just thought it would be better to suffer and live in confusion than to be stripped of choice and personality.
Now again although this story is "more formally" written in my churches doctrine it is still only a story. I think its entertaining so I choose this story over others as far as what I consider what really happened. (Kind of like The Life of PI, one of my favorite movies) and I hope it coincides with your question about the limitations and inefficiencies of divine power in advertising their gospel.
