One huge waste of time is red tape. Corporations love adopting procedures that are directly antithetical to getting work done in a timely manner, like “IT support” tickets that consist of getting access to an internal database, even if that database contains no sensitive information. These do not affect teams in an even way, since some projects’ critical paths will depend on these labyrinthine workflows more than others.
1) Things that everyone has to do like HR/Legal compliance.
2) Things that you should have opted to avoid like useless status meetings.
3) Things that are productive but have in-direct business value. That's largely a bug in the review process if it doesn't value those.