Tor, sure. i2p requires some proxy config in your browser and you need to run a service in the background explicitly. I wish they'd release a dedicated client like Tor does.
If you're talking about the Tor Browser bundle, I2P has this: https://geti2p.net/en/download/easyinstall
The current focus are new rust and go implementations, but embedding lib for applications is also in the roadmap.
I also agree on hindrance. I don't understand why they don't provide a simple docker-compose at least for daemon deployment for immutable management with controlled scopes. There is an image in the dockerhub, but no proper instructions. People have to spend several hours to ensure that everything works correctly.