People like this are so toxic that companies must eject them. They have no real added value, they merely harass those that should be helped to grow and learn as they evolve in their positions. Software engineering teams need collaborating peers and mentors not bullies.
What makes you think that a person with a degree in theoretical physics who is making their livelihood writing code is qualified to teach functional programming and more so address the (well justified) peculiarities of FP you are raising here?
Really dude, you got an undergrad in CS and you will teach us all these topics? I am exhausted by the available curricula that would make me a computer scientist, data scientist, machine learning guru, Python ninja and whatever else. All that by watching videos, attending online programs, mostly made by people who have zero content credibility yet they are able to put together a bootstrap website and search YouTube for videos.
Hardware changes the slowest so advances that affect how chips, processors and boards tend to be more predictable and long-winded. However, the application of these changes to different domains (e.g. IoT) changes rapidly so the underlying hardware platform may be "stable" but new requirements that need to be programmed (e.g. power efficiency, security, etc) will continue to evolve -- therefore requiring continuous learning.
How did you make the switch to Systems Programming?
How did you train yourself and what technology stack I (perhaps mistakenly) would think between the front-end, back-end and devops jobs, Systems programmers are a dying breed.
I hate to say this but working for startups really warps everyone's sense of level and career progression. Startup management cares to retain talent and they often give out titles (Senior, Director, VP) like confetti. If you really want to know where you are, the old-school behemoths (e.g. IBM, Lockheed etc) tend to have better (and more rigid) levels.