In a similar manner as Alpha Zero, Leela is growing by playing games with people and with itself (mostly). It is already a strong expert or low rated master at this point.
Youtube chess (masters) like ChessNetwork and Kingcrusher have videos of them playing it.
Not only is it like a totally different language than Perl 5, the most critical problem is that it simply wasn't popular.
All it would take is buzz... and millennials. Lots of millennials.
Generally, products that are the most popular aren't always the best. Better to just accept that now, especially before you invest much time in the space :)
...and it is where a lot of excitement is now. Excitement drives development (of tools themselves and general usage). Much of the time, it is for the best.
People tend to get lost in tooling, which I can understand.