I recently worked for a company with a large C++ codebase. For many years they relied entirely on asserts in QA builds to catch errors, no unit testing or production asserts. When I joined about three years ago they had just started to pick up unit testing, and would be enabling asserts in production “soon” (once all the most common ones had been fixed).

I left a little over a month ago, and the status on that was still “soon”. Some bad practices early on are just really hard to dig yourself out of.