Has the new Domane lost the plot by ditching IsoSpeed for weight savings?

The fifth-generation Domane weighs roughly 6.40kg without pedals or cages in the tested SLR 9 AXS 1x configuration. Do you think dropping the IsoSpeed decoupler and frame storage is a fair trade for a lighter bike, or does that gut what made the Domane an endurance machine? With 40mm tire clearance, can wider tires actually absorb enough road buzz to replace a mechanical decoupler? For taller and heavier riders, does a stiffer frame with less compliance risk more fatigue on long days in the saddle? And if Trek is chasing climbing-bike weight, how do you see the endurance category differentiating itself from pure race bikes without those comfort features? Would you take the $2,400 entry-level build over a similarly priced direct-order bike if you had to do your own tuning, or is the brand name worth the extra for a stock setup? Given the SRAM Red 1x groupset and 28mm tires on the tested build, is a 1x drivetrain really practical for loaded endurance riding or mixed terrain? Do you think Trek's move reflects what most endurance riders actually want, or is it just marketing aero and grams to people who'd be better served by a more comfort-focused design?