I used to do a lot of mileage when I was in college, and I responded really well to it. Most of my rides were over 3 hours, hell even my hard interval days were around the 3 hour mark. I'd spin an hour or so to my favorite interval road, kill myself for 40 minutes to an hour, then spin an hour home. My racing really went down the ****ter when I started working and tried a "time crunched" type plan. I think it was two-fold: I just like long rides, and the short, hard efforts for every ride really burned me out mentally, and also I think that my racing style was well suited to lots of endurance. I'm a terrible sprinter, so my typical strategy was just to attack early and often. Get brought back? No biggie, got lots of matches, I'll attack again in 3 minutes. It seemed like the time crunched plan bumped my power in the 3-8 minute range, but I had trouble doing it over and over again once my endurance base dried up.
This was 8 years ago though, I basically stopped racing when I burned out. I tried to get back in it for 2015, (had the same problem) and again last year (err same issue), but having a kid now and a pandemic have basically killed racing for me this year. Maybe next year?