Conti grip works only if you have superior quickness and speed, since your topspin strokes aren't as powerful, and your passing shots don't dip as much, or spin enough to bother another volleyer.
McEnroe can beat most top level 5.5's, using his conti grip. He's like 52 years old. Given a 22 year old body, he'd be even better.
But since the grass is always greener.....la la, if you chose only conti grip, you'd be doubting yourself constantly, because every other good player uses specific grips to hit each shot.
It would be tough to counter hard topspin high hopping shots with only a conti grip, since a slice is slower than a topspin ball, it creates less angle, and you only have a slice off that high bouncing ball.
You can try, but your groundies will lack pace with consistency.
And volley skills are not for every player. You need a hit and forget attitude, believing your net game will prevail in the end.
It is NOT the current winning tennis philosophy.