Other answers have already answered the question "directly", my answer will be about the underlying problem, which is about the gears not being hard enough.
One thing: non-enthusiasts like usually harder gears than enthusiast. Pedaling at high cadence is something a skill that is very useful, as it is actually less tiring than grinding. But it takes some practice, you can see it as an opportunity to train.
Otherwise, there's another technical solution that I give for reference (because it's not doable at low cost), which is to approach the problem from the cassette side: you can achieve the same result as a big chainring by decreasing the size of the smallest cassette sprockets (there are 10T sprockets and even 9T). But given your current setup and the current offering on the market, it will involve replacing the rear wheel, the cassette, the rear derailleur and its shifter for sure, and possibly the chainring.
Just for your information, the combination of 40T+ chainrings, flat bars and some offroad capabilities is really a niche nowadays (but not a high-end niche, as they are dominantly with alu frames and use entry level products). Compared to the Grand Canyon, they'll typically have much narrower tires (40-45mm) and less travel for the suspension. But that's a category that is not very fashionable now (to give some examples: Giant Roam, Trek Dual Sport and Marin DSX FS).
