I think that Strava does something weird when averaging power for the chart. My chart above was from GoldenCheetah with 3 minute averaging. The same ride looks spikier in Strava (not as spiky as yours, I think). But yes, I was actively trying to stay at FTP or below. When you're climbing a 3000 ft hill, there's no good reason to exceed FTP. With FTP of 190 W, my peak 5-minute power was 200 W and my peak 1-minute power was 214 W. (If you don't have premium Strava membership, you can calculate this for your rides in GC.)My FTP is around 260, as you can see even for a ride that I considered not super fast I spend quite some time above FTP. It also meant that I was regularly waiting for the group to catch up after hills or windy stretches.
65% FTP for 6 hours continuously is very different from 65% FTP for 6 hours moving time + 3 hours of rest. Strictly speaking, that's 65%*(6/9) = 43% of FTP for 9 hours. (But, if you can do 65% for 6 hours of moving time + 3 hours of rest, you can do more than 43% for 9 hours if you take shorter breaks, eat on the bike, and recover by coasting or pedaling at 50% of FTP.)
I see the point about performing above FTP in racing.