Disintegrate spell? Violates the conservation of mass. UNREALISTIC.
Titanic insects? Violates the Square-Cube Law. UNREALISTIC.
Storm giants? Violates the Square-Cube Law...again. UNREALISTIC.
Humanoids that live for several centuries? Violates the Hayflick Limit. UNREALISTIC.
Humans being interfertile with completely different species? Violates basic biology. UNREALISTIC.
Adventurers traveling for weeks on end without explicitly taking time to excrete waste? Violates basic biology...again. UNREALISTIC.
Adventurers spending tens of thousands of gold coins without devastating local small-town economies? Violates basic economics. UNREALISTIC.
Adventurers freely conversing with all manner of royalty in every population center they come across without suffering any consequences? Violates rules on decorum/protocol. UNREALISTIC.
Citizens who are terrified of dragons and fiends yet completely accepting of draconic bipeds and devil-spawn? Violates basic psychology. UNREALISTIC.
Citizens easily losing to one-on-one combat with moggies? Violates common sense. UNREALISTIC.
This was amazing. Thank you. I went down a multi-hour knowledge hole with this post.