Raigasm

No... it's because it's just a LOT faster not to have to move your hand between the keyboard and the mouse.

Unless you are typing one handed then there is inherent inefficiency in using a mouse vs. a keyboard command. Example: ctrl/cmd+c ctrl+v vs right click copy/paste.

Context: I've competed at a high level in CS/Valorant and voltaic platinum... mouse accuracy is not my issue.

Once you achieve relative fluency with using a given text editor or IDE then it is natural to gravitate towards using keyboard shortcuts.

Eventually, if you type decently fast (70wpm+, though that's slow by my standards but I'm not here to boast about the size of my epeen) many will find it frustrating moving between keyboard and mouse constantly.