I don’t get edit mode lag until 2-3 million but I don’t use blender for modeling or sculpting such high poly nor do I go so high in my scene either since I like to make everything in smaller modular pieces. I’m saving up for Zbrush for anything really high poly related. Got Designer and Painter for PBR texturing.
If that makes blender unusable for you. As you’ve brought up, maybe you should start paying for some tools.
[edit] why such an edit? I liked what you said the first time. You had a good point. I’m so confused.