It’s funny, I almost wish for the opposite, in the workouts at least. For me endurance riding goes with watching a movie, so I’d rather just pick a wattage in Z2 and stick with it. So I like that the TB workouts don’t have a lot of power fluctuations, and I don’t have to pay much attention (no ERG mode for me). I wouldn’t even mind a small step up to target wattage and then a straight line from there to the end!
That said, I somewhat agree that the overall plans aren’t inspiring, block one in particular. Seeing the same workout day after day each week is super boring. Maybe a small length progression within each week could help. But in the end, riding in Z2 on a trainer just isn’t exciting. A “polarized” plan would suffer the same fate: aside from one or maybe two exciting VO2 Max workouts a week everything else would be super boring. But I’m sure more people would choose it, because POLARIZED!
Fact is if I had unlimited time each week I probably wouldn’t feel the need for TR base plans at all. I’d just schedule 2-3hr Z2 rides as often as I could, and sprinkle in some threshold or maybe VO2 max as I got further along in the base phase. But for the majority of riders who need to make the most out of the 90min that they can take out of their day to train, the SS Base plans still seem like the right choice.