To take down a decentralized network with a bug you'd have to have every user on the exact same version and no way for them to simply role back to the previous version. I.e. nearly impossible.
Combine this with auto-updating clients and you've got a crashing software bug that brings down the whole network.
Agreed however that the centralisation point effectively still exists thanks to automated updates.
On a fully distributed network, that's pretty hard to do. DDOS works by having tons of nodes to attack with. That won't work very well when your target has as many or more nodes than you do.
Taking down a centralized target is vastly easier.
>Combine this with auto-updating clients and you've got a crashing software bug that brings down the whole network.
Only if I can't role my client back nor turn off auto-update.
> some teams can't continue to work even though git is decentralized.
I think you mean some teams won't continue to work because they don't know how to use git. If the de facto center goes down, a team is still able to use git to share changes with each other.
And IPv4/6 is decentralised, DNS makes it convenient for regular people to use. I would say DNS is decentralised as well, just the allocation of domain names comes from a few sources.