There’s a lot of discussion on this in different threads. Here’s a comment from Coach Mac.
I’ve had your same experiences. The All-Purpose Road plan did a great job of bringing up my AC and MAP, but my FTP stayed the same. I switched to the Metric Century Plan which included a lot more endurance and Z2 riding, and again, my AC and MAP came up some more, but my FTP stayed the same. Tho the results did vary between HM and FF. I consistently get a 20w higher FTP when doing HM instead of FF.
You can always do the 4 week Building Blocks: FTP Block plan. Or the Time Trial plan. Or the Century Plan. Something that focuses on longer rides. But like you said, genes are genes and maybe we’re meant to be Pursuit riders rather than diesel engines.
You could also try riding Cobbler 2 or 3 times a week and see where all the sweet spot training gets you.
Some of the plans (like the Century Plans) include both indoor and outdoor riding. You do your shorter focused sessions indoors and then do 2 longer rides outside.
