Back to things that I consider waste of time:
1. Bikeshedding Have you ever had a discussion about timezones with a solution designer? It's everytime the same: "We need localtime because system x is doing it and it's confusing to compare it" (no, you don't! You need to store them with timezone information and solve the human problem in presentation)
2. Discussing the need for bigger changes Yep. Your agile-developed system is running for some time and you see how it's being used and notice: It works, but it could be much better.
So you start a meeting others here describe as waste of time, because the result is "no" and the lasting result is, that somebody might keep the idea for later because there is potential (so not completely wasted).
But anyway, the time to prepare what you want to express in a way even managers can understand is annoying.
Coworkers often tell me, my ideas are inspiring and they would want to see them implemented. I feel it shatters because they are too big and sometimes cause efforts for other times because they have to change something so coordination is needed etc.
3. Finding workarounds for technical restrictions given by the company or project Development workspace is virtual and has a proxy with whitelisting for internet access. Things like Python's pip are useless. So you setup a proxy on your local machine and build up a reverse tunnel.
More common: Doing things on machines without root access. You have to figure out how you get information why something is not working but logs are not accessible. Nope. You have to ask someone with at maximum your understanding of the problem to assist you.
Closing: I consider myself as maybe 50% productive, but compared to results of others, I'm feeling much more effective, when I'm doing something. Not mentioning when I'm motivated and very concentrated. These are the moments where it feels like I'm getting the work for a whole week done in one day.
Thanks for reading