They got through at least 3 versions of the butterfly design, and kept using it from early 2015 through late 2019, before finally switching to a new (thinner than pre-2015, but still substantially thicker than the butterfly switch) rubber dome scissor design.

It would have been much better if they had figured out how to cut their losses and revert the keyboards in 2016 or early 2017, even though that would have taken a substantial redesign of the rest of the laptop internals.

Selling 4.5 years of laptops with keyboards that broke easily under ordinary use was a huge black eye for the company.