Welder/mechanic here, o-ring seals are commonly used in 3000 psi hydraulic systems and can have service lives of decades in some cases under brutal conditions.

I've seen fully welded connections fail under the same loads and conditions.

O-rings fail, welds fail, solder fails. Mode of failure is different for each one and you want to pick the one that best fits your situation, but an O-ring fitting isn't inherently worse than solder or weld for a residential application and requires a lot less skill to do correctly.

The main modes of failure that I see for o-rings are being cut on install, dry rot, or a connection not properly cleaned. If you leave a sharp edge on your pipe and it cuts your o-ring even a little bit, it very well might leak. But that's poor install, not o-rings being garbage in general.