My experience sounds very similar to yours!
I, too, am a complete sugar addict. When not being mindful, I eat sugar by the family-sized bag, tub, etc. I've now done a complete Whole30 twice and have done a few other attempts and mini-resets of varying lengths. I never experienced pretty much anything from the timeline. I didn't experience any of the adverse stuff like the carb flu or hangover or kill-all-the-things. Likewise, I never really felt like I got tiger blood or any of the other really positive things.
However, after doing a Whole30 and going back to poor eating habits, I started to really notice the stuff I did get. Because, once I lost it again, I recognized it for what it was. So, for me, the changes are subtle but kinda significant once I lost them again. Here are a few of them that I experienced:
Less pain in my joints (sometimes my knees or elbows ache when I hike or climb a lot; this happens less when on Whole30 but sometimes I don't recognize that because it was never really severe pain in the first place and never stopped me from doing those things)
Less of a morning and 3:00 pm slump (I never really got that increased energy that people talk about, but I did feel less tired if that makes sense; I started to lose the super sleepy slumps I would sometimes get driving into work and a few hours after lunch)
Clearer skin (I generally have pretty clear skin but it's much more "glowy" when on Whole30 than when I'm not)
My resting heart rate decreases
My heart rate doesn't go as high when doing exercise
So yeah, they weren't super dramatic for me, but they were significant and do actually affect my quality of life. A whole lot of subtle things add up to me truly just feeling better when I eat cleanly. But it was always hard for me to see during the transition.
So, maybe this is you. And hopefully this will help you dig a little deeper and perhaps recognize some things that might not be so obvious but are still important to you...