why

Idk. It's easier to open a new tab when context switching from n old one than to close old ones or navigate them elsewhere. Also I can't, like, close by domain like all Reddit tabs or what have you.

my phone hates it if you open more than ten or so

You should feed it more fiber.

how long did u have them open for

I think the oldest were open for about two months or so.

On my android phone (all android phones?) the tab count is replaced with a ":D" smiley when you reach triple digits. I usually try to stay in the 80-99 tab range, but at the moment I'm solidly into :D territory.

596 is beyond my wildest dreams.

My phone is similar and I only became aware of the breadth of my achievement when I decided to close them all at the same time, which is when my phone notified about my high score. There was like 20 tabs that had information I wanted to save but couldn't bother to dig them anymore.