Ryze is actually 100% unplayable in mid lane
Every other caster out-ranges you. Everything has a better early game than you. You can't reach your late game because of the above two issues, and 3/4 games are already over by the time you hit your power spike, even if you don't lose the lane.
The recent series of changes to Ryze made him significantly worse than he already was, because now you just get dived under your turret over and over, and get shut down so hard that you have no chance of scaling. You have no way to protect yourself or retaliate, because your range is so low.
He's now forced to go top lane, because he can only function by bullying melee champions who can't retaliate. This is not healthy game design, and I'm actually amazed at how incompetent the people who made the recent changes to him are.