Mixing GRX crankset with Deore groupset on 2021 Trek Dual Sport 4 I'm riding 2021 Trek Dual Sport 4. It has almost full Deore groupset, except crankset. Here is the full spec list:

Shifter: Shimano Deore M5100, 11 speed
Rear derailleur: Shimano Deore M5100, long cage, Shadow Plus
Crank: ProWheel alloy, 42T, 175mm
Cassette: Shimano Deore M5100, 11-51, 11 speed
Chain: KMC X11, 11 speed
Pedal: Wellgo Black

I'm really not happy with this ProWheel crankset (from my point of view, it is unacceptable to put this noname $20 crankset to the $1200+ bike), therefore I was looking for an upgrade from day 1. As I'm utilizing this hybrid bike as intended, riding 70% ideally paved roads and 30% light trails, 42T is a must for me, so I cannot put, for example, Deore XT crankset as it's only 36T at max. Hence, I've chosen a Shimano GRX 1x11-speed crankset (FC-RX810-1 to be precise). However, I don't know if it will fit and there is no reputable bike tuner around, just a few ready-to-go bike shops. So, could you, please, help me understand if I'm fine replacing just a crankset, should I replace anything else as well or maybe consider other options for 42T?
Thanks.
It will be fine, as it's just a one-by ring for 11speed. You could also use a sram apex1, a miche graf, or any number of other options.
You will also need the matching bottom bracket for your chosen crank.
Fwiw, most manufacturers spec a cheaper crank, wheels and/or brakes to meet a certain price point, to avoid cheapening the frame or headline components.