I don't doubt your experience, and I don't have a survey of industry standards. But I will also say that experiences 14 or 25 years ago are not a reliable guide to HR choices in the 2023 tech industry.
I didn't say only high profile companies gave severance. I'm saying 3+ months is rare and it seems normal because it is a marketing tool used like this.
Also to restate, my experience translates to what is currently happening in tandem with the last two periods. I know someone who was recently let go getting 4 weeks after 16 years.
But my friends have been laid off, and I've yet to hear of any of them getting more than 1 week per year worked. But I don't have any friends that work for big tech (I live in the Midwest, a lot easier to not know anyone in big tech here). A lot of insurance, health, and financial companies around here, not too many Facebook or Apple or Netflix offices.
I think you're being unrealistic as to what the industry as a whole is like. 1 week per year is not uncommon. I've been doing this 26 years and have had many dozens of friends laid off during this period, back in 2009, and back during dot com.