I built a bespoke IOT stack that currently runs over 10k devices and a full production line interface / deployment for a factory we used in china. I'm not going to define what "senior engineer" is, but this was done largely solo with engineers I managed to maintain it.
Based on your responses, I think your soft skills / people skills are letting you down. I would recommend working diligently on how you interact and communicate so that you do not come across as arrogant, dismissive, or out of touch.
