With most tech career advice on the internet, I would check to see if it was written before 2022. If so, I'd take it with a grain of salt. I wrote tech advice in the ZIRP times. It was a very different market. Negotiation is still a valid tactic but there's a lot more to lose and a lot fewer offers than in 2021.
Negotiation isn't a tactic, it's the basic thing you are doing.
Depends on your position. I was employed but the company was going down the tubes when I got my last job through a connection. I didn't really negotiate and the one thing I would have liked to have negotiated (paid time off) was made clear was not on the table even before I said anything. And the offer was not FAANG levels but was incredibly good relative to what I was making.