One of the fascinating things about lean manufacturing is that few companies outside of Toyota (let alone manufacturing) have ever successfully gone lean. Projects like NUMMI were a failure. Only some of the dead simple lessons of lean ever got adopted.

Agile itself as a set of principles is still invaluable. But it's been cargo-culted to death. The "agile" frameworks that exist today have been completely divorced from the principles. Tools like Jira are now so complicated and process driven that I would argue they are anti-Agile.

I think the key that makes process improvement work in manufacturing is that the production line is continuous, and the measuring of outcomes is independent. Car quality, customer satisfaction, units produced, mistakes, etc.

In software, the outcomes are often nebulous and unmeasured. There are not discrete, matching outputs over time. So management becomes obsessed with micro-managing and controlling the inputs. Ticketing, points, assignment, etc. Agile has become a system for creating dashboards more than outputting quality code.