Startup is a living verb, not a has-been adjective.
I always like to describe my company as a 3 decades plus young startup. To my mind, the current ongoing restructuring process of the global economy — which started in the pre Covid-19 era due to de-globalization, Internet induced changes and automation — has torrentially changed the landscape of work. It is forcing every organization, city and even countries to start over and reinvent themselves. Hence, ‘Startup’ is an action oriented agenda, one step at a time, one day at a time. Applied to individuals, organizations and countries. It is a daily living and breathing verb.