I'm still on 9.x in some systems and it's running great. I find this kind of sentiment a bit weird anyway: PostgeSQL 17 has been out for a couple of weeks, I'm certainly not in a rush to upgrade anything unless I need to. Never touch a running system is as valid as ever and on top of that I'm not a full-time DBA itching to upgrade as soon as possible. With containerization it's also more common to have multiple and right out many DB instances, I won't be going through all of them until someone requests it. Security updates is a completely different matter, but major versions? Don't get the rush, the developers will come around sooner or later.