This is exactly why you should be in a standup. "Secret" time planning and developing "cool" features. Someone has taken the time to carefully plan the features

This is exactly why you should be in a standup. "Secret" time planning and developing "cool" features. Someone has taken the time to carefully plan the features required for a project and make projections of how long that will take and how much it will cost. There may have been customer feedback on what features are required, or possibly even a customer is paying the costs of certain development work. And you think it's your job to just secretly decide that you don't want to do that, you'd rather spend time working on something cooler that the customers might not even want or perhaps conflicts with other project plans. I'm all for devs being involved in the process, but devs absolutely should not be making secret solo decisions on what features to build without consultation. The last thing I want is to be surprised by a new feature just showing up unplanned in a project. I dunno, perhaps you work on internal software for a small group of specific known users who sit a few desks away from you and that's acceptable to them, but for any team building a customer facing product that attitude would be a nightmare to manage.