Effects, draw distance, resolution, polycount - there are a lot of ways to tune performance. Capcom don't WANT to change the look too much.
How much power have the low end computers running MHW?
GTX 760 is the minimum GPU listed on steam, which is a 1.8TF-2.2TF card.
It also needs 8gb of ram + 2gb vram card.
Basically listed Minimum requirements are WAY above the Switch, and marginally above the PS4/XBO on ram/gpu and substantially above ps4/xbo on cpu.
Getting the game to run on the Switch Docked, but especially in Handheld, would be an absolute nightmare.