If you had to do one,the normal shoulder width or a sumo stance or something else, which one would you do for general strength training?I have noticed that glutes activation is more in the wide stance but overall I can life more weight in the conventional way.
Moving past the obvious "it depends" answer, please consider the origins of sumo deadlifts. Now consider the physiology involved. Putting these two things together, we get an answer: "the best stance" depends on your specific body measurements first and foremost.
How long are your legs, how short/long are your arms? How do your limbs stack up against your torso? How deep do you have to squat to grab onto a barbell and keep a neutral back? These questions will inform the best stance for your body.
But don't forget that variety is key: after doing sumo for a long period of time, a conventional deadlift may become better temporarily just to shake up the routine.