In other parts of this thread, I've explained why we don't use I. Let me gather them for you.
1 - Redundancy. Imagine a list of bullets that start with the word "I".
- I wrote a playbook for product implementations.
- I managed the project...
- I oversaw a team that...
Hopefully by now you see this wouldn't be a fun read.
2 - Necessity - The resume is about you, not others, so we don't need to say that you (I) did the things on the resume. That is understood, and why 'implied' first person fulfills our needs while also reducing the content. If I ask you what you did today, you can just say "Watched TV, mowed the lawn, ..." - you don't need to say "I watched TV, and then I mowed the lawn."
I hope this helps, and maybe we can put this to bed.