Why does work still bleed into my whole life even with boundaries?

You have started setting boundaries, and that is real progress. The bleeding you still feel does not mean the boundaries failed. It means the habit of carrying work everywhere is older and deeper than the lines you just drew. That takes time to unlearn. Often the leak is not the hours but the mind. You clock off, but the worry follows you to dinner and to bed. A boundary of time only holds if you also give your attention somewhere else. Otherwise work fills the quiet. Pick one part of your day that is fully off limits, and protect it like it matters, because it does. When a work thought shows up there, notice it and set it down, gently, again and again. You are not failing. You are training. Each time you set it down, the line gets a little stronger.