Yes, I would. The thing with popular online training platforms is that they are geared toward the “time crunched” population. This means the time component of training is under-represented and the intensity component is over-represented. The TR plans are predicated on going harder, not going longer.
Yes, hopefully your FTP will be improved every time you start a SSB plan, however, the Sweet Spot zone remains constant. That’s to say, SS will always be your SS, regardless if your FTP is 100w or 400w. You could also say that the cemented interval durations will have a diminishing return the higher your FTP goes – a 12min SS interval could have a much more profound effect on boosting a 100w FTP than it would a 400w FTP. That “progressively more kJ”, relative to your FTP, will not change all that drastically.
Why not? In fact there are some popular coaching platforms which do include daily “3 hour SS intervals”:
Sure, those TiZ amounts are for Conti/WT pros, but as you can see from the chart, TiZ is progressive, not only through the ranks but also through the season. Let’s say you are 15 years old and just starting to ride a bike competitively, with the dream of becoming a pro racer in 6 years (age 21). The range for your SS TiZ stretches from 15 minutes to 5 hours(!) – per day! If you spent those same 6 years following TR plans, you’d never ever extend your daily SS TiZ past a maximum of 90 minutes. Ever. But then again, TR’s core user base isn’t trying to become pro racers, so maybe the limited intervals are what works. 