It's impossible to tell if Skype becoming irrelevant was due to new bloated features, new features that were badly implemented, or just that their users wanted

It's impossible to tell if Skype becoming irrelevant was due to new bloated features, new features that were badly implemented, or just that their users wanted to play with a new shinny tool that happened to be good and gradually moved there. They could have stayed put without adding any new features and would still be beaten by Discord.