This series is one of my favorite series (one of the few series I've actually read the WN/LN) but reading it monthly vs binging it, I can definitely see how people would be really at odds with the school arc. It's a very odd thing to say how the school arc is probably one of the most important arc because it sets up literally every arc after it. Almost all the named characters are going to be important characters with several major plots centered around them but I do understand its hard to be fine that the last 2 years (since the MC met Orsted) and probably the next year are all chapters dedicated on world building and setting up for future arcs.