It's not a "serious" project. I chose Go specifically because I like the language (and Ebitengine is super fun to work with) and I like the idea behind ECS. I made games with Unity before, which you could consider a "serious" engine, but the fun of development is nowhere near what I experienced here.
Thinking about what would be the most efficient engine for the game would kill all the fun for me and the project wouldn't exist. :)