The biggest hidden assumption I see is that we expect other people to be trying and learning things in the same way we do.
Experienced devs will write code to improve their own understanding, they will create tests to improve their own understanding, they will do research, they will do a lot of learning and all of that rarely gets talked about at standup or in a pull request. This work never shows up in a planning or budget meeting.
I see junior devs getting stuck hard on delivering production ready code - which is the WORK PRODUCT that we want; but that is not what the actual work of software development looks like. A lot of junior devs are hesitant to do throw-away work that does not get committed to source control - they feel like someone out there knows the answer and they just have to find them. And for a long time, that works - they can find someone to provide the answer they need, they can find a senior dev who glances at the code and fixes it effortlessly.
This whole thing is exacerbated by managers with no or minimal dev experience, who also confuse work product and tracked work items with the actual work of producing software.
(And if you're wondering who 'junior devs' is, it's me. I'm junior devs.)