Could you explain why i2p works better than tor for the type of attacks from the article?

It's not and it's much less anonymous.

This is plain wrong: https://geti2p.net/en/comparison/tor

That link doesn't support your statement. Tor is more anonymous than I2P.

Almost everything in the section "Benefits of Tor over I2P" is about the size of the network. Technically I2P is more secure, it just lacks users.

I2P allows to increase the number of hops to any value.