I'm in favour of slowing down the game in general. Conditions would still be equal for all.
Oh no. Every attempt to slow down the game so far has made it so that the ball could be hit harder, faster. Now I get why you want to raise the net. But why would raising the net make the game slower. Sorry, as I see it, anything that makes the ball go slower is an opportunity to let the person hitting move to the ball better and hit it harder-faster. Also, higher net would mean more mid-distance looping and the need for more spin. All it would do would be mess up the players with funny rubbers and lower level players who cannot generate enough spin. Higher net would also mean that you could not get your serves as low and so they would be more easily flipped. Pushes would also have to clear a higher net and therefore would have to bounce higher making them more easy to attack. A higher net, once the higher level players adjust to it, could make the opening attack end even more points and mean that there would be less rallies.
Why not just make everyone play with sandpaper and hardhats?
No, please, don't do that! That would be boring. The game is fine how it is. Leave things alone. ITTF has done enough to mess up the game with larger balls not to mention the plastic ball that will be coming soon.