Feedback "new" Input System replacing old Input Manager

So Unity announced the Input Manager was to get rid of in the next version over 2 (?) years ago only to realize its replacement wasn't production ready.

I switched to the new Input System around 1.5 years ago, think I got a grip of it, found some bugs (which i thought were relevant for anything more advanced than just a keypress for which nIS wouldn't be needed but weren't fixed even 1 year later) and now am pondering the state of the nIS.

I had the impression Unity let only 1 human work on the whole Input System for 3 or more years. Is the update and fix rate now < 1 year?

The documentation of core principles was partly scattered and the API's multi-layeredness was complex - is it easy to grasp and follow now? i obviously don't bother to check.

What do you, reader of this post, observe and feel wrt the nIS?

Is the nIS something an inexperienced or not-multiple-PhD having "programmer" can happily easily achieve every possible scenario with fast? (because if he/she can't, why have the nIS?) Or has the time come to write for Unity to do a nIS anew? (and give them the basic information what they "only" need to offer -- the Input Manager sort of worked for 10 (?) years and assisting Assets exist(ed) I believe -- and thus should be able to deliver complete and completely working within 6 months).