Define 'fast' and 'these days'. Lots of companies are affected by bus problems, but I'm not so sure they're successful at dealing with it. I'm also not sure this is a new phenomenon, and it's certainly not universal. If anything I can think of a couple of projects that suffer from too little turnover, and the resultant echo chamber.

As for 'dealing', look at all the status Google services have lost in the last ten years due to systemic problems with valuing novelty over stability. There are perverse incentives not to maintain things you have delivered, even if you are still at the company.