Its slightly funny to me when there is a setting with absurd levels of fantastical bullshit and the main character is like just a normal guy. Even better in rpgs where the rest of the party is like a uniquely different race, group, etc. You'll have like Gurgabold the Great (Noble bright-green skin and frog-like features), Rendlesham the serene (just like, distinct enough elf that has a druid's wildshape from d&d) , Noctor (a bat guy or something), and Greg, the guy from down the street.
Notable examples include:
Finn the Human (Adventure Time)
Steve (Minecraft)
Will/The Protagonist* (Metaphor: Refantazio)
The human fighter from my D&D party
Any star wars protagonist
Spoilers and explanations below
I mean finn is just a normal guy where almost everything in Ooo is fantastical (living candy, fire people, etc), which makes Finn stand out more as being a normal human
Steve is like the guy of minecraft. There's a dragon, zombies, giant spiders, pig people in the hell dimension, and Steve is just like, a normal dude (absurdly strong, technically speaking but...)
Will is technically not a regular human (although he basically is, being a member of the Elda race) and while he is a magical being and able to do cool magic and stuff, his race is the most like normal humans.
Human fighters are just kinda person who is good at swords. Considering we have a half elf druid, drow cleric, and dragonborn paladin (me), its kinda funny we just have random guy
Star wars has so many different unique alien species but the protagonists are almost always some humans, their droid(s) and maybe the weird non-human they picked up on they way.