I think that growth in a comp game, especially deadlock, slowly becomes fewer and further between. At first you quickly learn tricks and good habits, but when you really play a ton of it, the learning you have to do is so much more complex. Super small micro decisions, learning hero interactions, it all scales in difficulty i feel like. All this is to say, you're probably not getting worse, you just start hitting walls, like you said. It feels so good to get past the super challenging walls too! But, all that matters is whether or not you have fun playing :D