These internet corps are usually extremely bloated and have ridiculous amounts of unproductive diversity hires people employed. Plus, they need huge, hip "campuses" for all these people. Considering they are in the most expensive part of the country that quickly adds up.

On the income side, they themselves fueled a climate where companies are less interested in running ads, which is likely their main income, e.g. due to lockdowns or because one controversy chases another which makes advertisers skittish.

They also took on a lot of venture capital money. That needs to be repaid, with interest, and investors aren't content with they usual interest rates.