The point is that 'just keep trying' would not have been a good strategy.
Yes, it’s possible that there are some concepts we have yet to think of.
See: https://numinous.productions/ttft/
The explanation of how hard it would be to come up with Arabic numerals if you didn’t already have them covers this.
However the point here is that we can learn from this, and we now know a lot more about how to do hard things.
‘It’s too hard and we should give up’ (the countervailing straw man) is even less supported by history than ‘keep trying’.
The point is that 'just keep trying' would not have been a good strategy.