No skin in this game cause I don't have a commuter style ebike. But....I do have opinions based on what I've read here & with ownership of the gates belt drive system.....
The Enviolo is always compared to the Rohloff in the ebike game. Suggest you look over the Riese and Muller owners section here:
https://electricbikereview.com/forums/forum/riese-muller/ & look specifically for threads talking about the Enviolo vs the Rohloff systems. Bottom line: It appears to be a heavy, well built piece. It's drawback is it does not have the wide gearing percentage range that the Rohloff has. And I suspect at looking at the cassette on the Trek, the Enviolo would be hardpressed to beat the climbing ability of that Trek you have. In addition, riders acclimated to the stepped shifts of a cassette, Rohloff or Pinion drive would have to get used to the non-stepless Enviolo.
I see the Trek also has the ability to piggyback an additional 500wh extended battery, making for a terrific day touring bike.
Onto the Gates Carbon Drive: I have one on my analog Trek Soho DLX, coupled with the Shimano 8 speed Nexus IGH. Personally, I love it. However, though I really, really keep my bikes clean after each ride, I found the belt always develops an annoying squeak after a day on a dusty towpath trail. A matter of cleaning the belt with soapy water, yes. But out on the trail, it can be a bit irritating. YMMV.
Myself, asked between the two, I'd take the Trek and get the 500wh booster battery.