I've tried implementing I2P and my opinion after that experience is that it seems intentionally unusable.
Everyone, even I2P, is nowadays pulling you to Tor.
Instead of feeding that kraken I've just implemented our own network. For sure not as polished, but at least works for what is needed.
Which version did you use? I2pd is usually included on Linux distros. Just install it and enable the systemd process (sudo systemctl enable i2pd) then you should be good to go. Use SOCKS proxy port 4447 on your monero wallet to connect to i2p nodes. Way lower bandwidth but good For alternative.
For browsing eepsites use HTTP proxy port 4444 on localhost on any browser and you can go to any eepsite. Try http://notbob.i2p to find them.
This was on Android, very difficult to implement and then too heavy to use both on speed and battery of the device.
There are technologies that didn't exist at the time like NAT hole punching and WebRTC. With those two features alone is easy to achieve similar results with a simpler approach and far higher bandwidth.
For example, two phones can directly connect with each other no matter in which networks they are, or you can configure multiple jumps when needing to access Internet sites.
