I've got ~5k+ tabs, and I've also seen basically zero crashes in the last decade. I'm on Macos, not very many extensions though one of them is Sidebery (and before that Tree Style Tabs) which seems to slow things down quite a lot.
I likely don't need all the tabs. Some were opened only because they might be useful or interesting. Others get opened because they cover something I want to dig into further later on, but in this case it's the buildup of multiple crash>restore cycles. Eventually I'll get to each tab and close it or save the URL separately until it's back to 0, but even in that process new tabs/windows get opened so it can take time.