Since last patch, the client CPU usage got DOUBLED

And it makes the client extremely laggy, both input and animations wise. I mean, it's using up to 60% of my CPU which is INSANE. Why does a CLIENT and not the game itself use so many resources? It's embarassing how poorly optimized it is to be the client of the most played game in the world.

Did someone make it to work decently after the patch? Right now I can't even open other apps otherwise I can't pick or ban lol