Corporate reputation. We don't need licensing in the tech industry to build things like search engines, ai and space rockets because hiring standards are a form of private sector regulation (over the workforce). Reputation is sufficient to ensure the best companies rise to the top
Building failures happen after decades, when the original engineers are retired or dead. Internet products sink or swim in months. I don't see how those timescales are remotely comparable.
Engineering companies stick around for a lot longer than tech firms though. The people who still work there and would like a long career will be looking out for mistakes.
