FWIW, I had the 2015 MacBook and have a 2018 MacBook Air that I bought ~4-6 months ago?
I actually liked the MacBook keyboard, but I did have to have it serviced several times.
So far, the MBA keyboard has had zero problems.
And I think the 2019 even had a very minor tweak / improvement over the 2018 model.
My guess is that Apple has largely, if not entirely, “solved” the problem of the butterfly keyboard, but at this point it’s reputation is ruined, so they’ll have to replace it anyway.
However, I would not have any qualms about recommending the current generation of MacBook Air – with the obvious caveat that "sometime in 2020” the MBA will probably get the new scissor keyboard, but if you need one now, then you need one now. Not to mention that no one knows if/when the MBA will be updated with the new keyboard, although we all suspect it will.