The thing is, the Toyota methods relies on people on every level to work to improve processes. If you're an employee and know you'll be there 10 years down the line or even until you retire, you have an incentive to improve said processes.

Now check most Western companies: since the 70 / 80, everything is about reducing headcount. Lay-offs, outsourcing, offshoring, now the concept of spending your whole working life at the same company feels like a fever dream. So why would an employee try to improve things for the company when they know there is no future for them there? Better improve their own career and future prospect. So yeah, things like Kaizen are doomed to fail until things change.