Yes, using TOGA on every takeoff would increase the stopping margin.
If that is you only contention, then by all means, I hope you always use 12K plus foot runways, anything else would be unsafe, right?
As plenty have mentioned, large aircraft engines are normally trend monitored and that is what determines when overhaul is neccessary, not a number of cycles or hour limits.
Is Flex/derate unsafe, the numbers would say no. Plenty would say, as they have here, that the greatest stress is put on an engine when it operates at TOGA power.
You want to use TOGA on every takeoff, by all means, nothing can be said that will change your mind. The airlines will continue to use Flex/Derate and the large engine manufacturers will continue to recommend it!