How long of a notice period is considered reasonable probably varies drastically between different countries, different industries, etc. So the advice should largely be just do what is the norm in your environment to avoid burning bridges.
I have only worked for FAANGs and other big pre-IPO startups in the west coast for the past 15 years. I have quit like 5 times now and I have always offered only a 2 weeks notice. That is considered normal in these places. I have never burned bridges (I have gone back to work for the same company with the same people even).
I have only worked for FAANGs and other big pre-IPO startups in the west coast for the past 15 years. I have quit like 5 times now and I have always offered only a 2 weeks notice. That is considered normal in these places. I have never burned bridges (I have gone back to work for the same company with the same people even).