It’s harder to get there than most posting here lead on. They probably got there so easily that they don’t even realize that they are in the top 3% of their age bracket.
One can look at the bell curve charts of TR cyclists that have been posted. It’s a small percentage in the 40-50 age bracket that get above 4 watts/kg. The percentage gets even smaller in the next age group which tells me that there is probably a big gap between 39 and 49.