This is wrong. It's not inherent in the meaning of the word "breakthrough" that a breakthrough can occur only when someone has gone against the grain, and there are countless breakthroughs that have not gone against the grain. See: the four-minute mile; the Manhattan Project; the sequencing of the human genome; the decipherment of Linear B; research into protein folding. These breakthroughs have largely been the result of being first to find the solution to the problem or cross the theshold. That's it. That doesn't mean the people who managed to do that were working against the grain.
> Yet we often act in reverse, we discourage going against the grain. Often with reasons about fear of failure.
I don't know which "we" you're referring to, but just about everybody would agree with the statement that it's good to think creatively, experiment, and pursue either new lines of inquiry or old lines in new ways, so, again, your claim seems clearly wrong.
If you're discussing just scientific research, though, sure, there are plenty of incentives that encourage labs and PIs to make the safe choice rather than the bold or innovative choice.