On the subject of low-security locks in commercial applications, I've just started a job where part of the work involves facilities management, key-issuing etc.
There is an entire tub of old keys, including two Grand Master Keys from a patented system (GEGE) that are sitting unused. All but one cylinder (the common entrance gate) have been replaced and they just hand out any key from the tub as a gate-key.
The new system is ISEO locks, cut on a universal blank. One of my first jobs was to get the new GMK cut at Timpsons

(Apparently they were very impressed how cheap this system was compared to the last, and they had to have a complete re-key after "a couple" of GMKs went missing)
Based on the numbers of keys in tubs in the office, there have been two or three systems that are no more, including 5 lever BS locks (not a single one left on site)
I don't even want to consider the electronic safe with wafer-lock override...