It’s not that they are unfriendly.
But they are 100% there to represent the company’s interest and not yours. If there is any way, to… turn a situation into something where the company gets more money out of it and you get less, it’s their job to make that happen.
In theory they should have employee retention in mind. In practice, nobody does their HR that way anymore.
All my interactions with HR have been “professional polite” and appropriately friendly. There is no reason to be unnecessarily mean, they are also just doing their job.
Easy, join the cult of linux and bow to the power of the cult leaders: “doing math very fast”. BEHOLD.