Open world RPGs tend to be a jack of all trades because you can follow (many) different paths and have various means to complete tasks, which makes it difficult to have good mechanics for everything.
I'll give a simple example. Stealth is usually an option in RPGs, which means such a mechanic must be implemented. Usually, it's just a simple indicator of how well hidden you are. This is enough for a normal RPG, but wouldn't suffice for a game that focuses on stealth (e.g. Thief/Dishonored). Then you have fighting (melee/ranged), driving, hacking, talking, exploring (jumping/climbing), mini-games and whatnot.
When you can quantify every aspect of the game, which mechanics can you use the most (or have to)? Driving is a support thing, but stealth could very well be the most important for a cyber-ninja. Or maybe you want to talk or hack your way through the game?
Then how important is combat? Dunno. DIsco Elysium is a RPG without any combat (except via dialogue choices). Regardless, if the devs want to add a mechanic to the game, then either make it memorable or make it forgettable. Or to put it bluntly (and more clearly), if it's going to suck, then, at least, make sure it isn't annoying. Case in point, the Witcher 3's combat, which was mediocre, but still good enough to have an immersive fantasy RPG.
I'll give a simple example. Stealth is usually an option in RPGs, which means such a mechanic must be implemented. Usually, it's just a simple indicator of how well hidden you are. This is enough for a normal RPG, but wouldn't suffice for a game that focuses on stealth (e.g. Thief/Dishonored). Then you have fighting (melee/ranged), driving, hacking, talking, exploring (jumping/climbing), mini-games and whatnot.
When you can quantify every aspect of the game, which mechanics can you use the most (or have to)? Driving is a support thing, but stealth could very well be the most important for a cyber-ninja. Or maybe you want to talk or hack your way through the game?
Then how important is combat? Dunno. DIsco Elysium is a RPG without any combat (except via dialogue choices). Regardless, if the devs want to add a mechanic to the game, then either make it memorable or make it forgettable. Or to put it bluntly (and more clearly), if it's going to suck, then, at least, make sure it isn't annoying. Case in point, the Witcher 3's combat, which was mediocre, but still good enough to have an immersive fantasy RPG.