Sometimes fixed camera angles makes games easier to control as long as the fixed camera angles are consistent and not imposed on you in sudden forced exceptions to the camera angle rules
It is absolutely horrible when you must control the camera angles for the game while moving and then the camera angle is changed on you by some programming thing that over rides your control whenever you reach some part of the game
This was not a problem in old games in which the player could not directly choose the camera angle but the camera angle changed in response to the position of the player
This was also not a problem in games where a single unchanging plane of view was used
Landstalker for Sega genesis
The first Sonic the hedgehog for Sega genesis
Commander Keen
Wolfenstein 3D
Doom 2
Lands of Lore
Dungeon Hack
Ancient Domains of Mystery
Angband
Dune 2
Warcraft 1
Warcraft 2
All those games did it right