[Ygor]

Also - keeping the stuff running, and making sure nothing ever breaks, is a different problem when you just want to maintain the current state of the product and keep it stable, vs when you want to change it.

Many tech companies are optimising for having hundreds of new features and products developing on top of the current stack, and allowing quick iterations, taking bets on things that might or might not have the market for it.

You can fire all civil engineers in the country and bridges will not collapse immediately. But you won't get any new bridges built. Also - at some point you might learn which ones had structural issues hidden by maintenance.