Let’s say we left one single very smart guy (not necessarily with the knowledge: they may be able to understand hard stuff when taught it, but not know it already) alone on a copy of the earth. That person is also immortal. Could that person, by themselves, gain back all knowledge, maybe also experimental, or even surpass that is already available to us right now, before the planet gets inevitably engulfed by a sun turning red giant?
Did you just start watching/reading Dr Stone?
If not, give it a shot, it’s obviously not realistic but it’s basically an anime answer to your question lol
the problem with Dr stone is senku already has the knowledge