Can I understand by companies start ghosting people after an interview?

I have been doing these interviews cycle with one software company and it been 3 interviews one of them is 1 hour and 45 minutes with presentation and case study I should represent in front of multiple people , so that took so much time and effort , the least they can do to show respect is even to send rejection mail but just to ghost me and even when I try to send a mail asking for feedback they don’t reply , that sucks that the worst any company can do to show how un-professional they are and don’t have any systematic process.