Personally I came from a C background so I tended to use deps more sparingly.
In the end it's a bit of a balancing act—lots of dependencies is a larger opportunity for these kind of supply chain attacks to affect you. Copying stuff into your repo protects you from that, but it also makes it way more likely that you'll miss security fixes, unless you're actively looking for them. Re-implementing what you need is also viable but it slows down the dev process.
Culture has a lot to do with it.