I remember when I prepared for system design interviews in FAANG, I was anxious I would get asked about Paxos (which I learned at school). Now that I'm working there, never heard about Paxos or fancy distributed algorithms. We rely on various high-level services for deployment, partitioning, monitoring, logging, service discovery, storage...
And Paxos doesn't require much maths. It's pretty tricky to consider all possible interleavings, but in term of maths, it's really basic discrete maths.