I understand the downsides of Moltbot better than the upsides. What does it have that running a coding agent in a VM doesn't give you?

It's not for that, the hype's not from SWEs, it's the next wave of tech savviness seeing some of what's possible (/riding up that peak before disillusionment trough).

There's nothing new, it's 'just' conveniently packaged for the gamers and /r/battlestation owners and distro-ricing crowd to install and run. There'll be similar hype waves where they too are confused because nothing's new when it's easy enough for our not-technically-inclined older relatives etc. to run somehow (not from GitHub!).