Working as a system administrator for years I understand the importance of a clean system without clutter from old backups, bak files and entities that are no more in use. Those unused entities often confuse me when selecting the right entity. A slight difference in naming a entity in esphome and again a new piece of clutter that often can’t be removed anymore. Not after a reload, restart or even a reboot. At the moment I have far to many entities cluttering my system.
I would propose for a stronger method of removing unwanted entities then a greyed out delete button. Info why the button is greyed out would help but just a hard delete will help also.