Well...
Scientific Genius: built his own time machine, something that ol fukk boy Reed Richards couldn't do.
Mysticism: Second only to Doctor Strange when it comes to magic, and he barely even uses that shyt.
Diplomatic Immunity: Leader of his own country. Dude can't even be touched when he steps in the US. So trill
Got his mom's soul out of Hell. Just another Saturday for Doom.
Went to Wakands and crushed the buildings: Entered the Vibranium vault just by being the shyt.
The Egyptian Cat God that was guarding it searched Dooms soul and was like, "shyt....he's right" and let Doom into the fukking Vibranium Vault.
And while Reed was out neglecting his wife again while she was pregnant, Doom came in, delivered the baby and saved Sue. Doom even named the kid. (Valeria)
My man stole The Beyonders powers. Look that shyt up and see gangsta that shyt is.
Basically, the only reason Doom doesn't rule the world now is because he doesn't fukking want to.