This is basically 1:30:00 of the guy explaining why Cyberpunk 2077 has more choices and RPG elements than the Witcher 3.
Too long to watch this now.
But yeah, what is an RPG is a philosophical discussion that has been done to death. All i can say is what is an RPG for me, and is not just role play somebody. You do that by default when you play a character in a game.
For me RPG as it has been adopted in video games has nothing to do with how the game handles the action part of the combat.
-It can be turn based, like it is on Pen and Paper and Tabletop RPGs (which is the only way possible really)
-It can be pseudo-turn based (usually you control a team and often you can use the pause button to make decisions)
-It can be real time isometric, or hack n slash (diablo clones)
-It can be Third Person Perspective Action Based (Souls series, The Witcher)
-It can be First Person Perspective Action Based (Skyrim, Mass Effect, Borderlands, basically all the FPS - RPGs)
It has to do with the ability of your character to progress towards a certain direction and create a "build" that severely impacts the gameplay. Mainly in combat but also outside of combat. But in combat should be the bare minimum for the game to be considered an RPG.
That's for me. My definition. With my criteria Cyberpunk is "more" of an RPG than the TW3, or even a deeper RPG, despite being an inferior game. Again, changing the outcome of the story through dialogue choices to me have nothing to do with a game being an RPG. If your BUILD matters alot in the dialogues, that in turn change the outcome of the story and lore, then sure.
Edit: Also deep RPG elements, or alot of RPG elements yada yada yada have nothing to do with the actual quality of the game. This is a seperate discussion.