In case anyone wants to know specifically why this is crazy: here’s a NASA article about magnetic pole shifts/reversals. The short version is:
Magnetic North Pole was identified about 200 years ago and since then it’s constantly been drifting so “Pole Shifts” are a constant reality.
Complete reversals (where N and S swap) happen every 300,000 years or so on average (varying a lot). The last reversal was actually 780,000 years ago, so I’m not sure what societal collapse this guy knows about from WAY into pre-history.
The Earth’s magnetic field has declined in strength in the last 200 years by about 9%, but it’s still twice as intense as it’s million-year average and not going anywhere anytime soon.