However, they can simply narrow the definition of "FSD". Remember, level 5 as stated doesn't include parking nor does it include strategic decision making. If they say that FSD means Level 5, then they are off the hook for providing the capability required for many everyday aspects of driving. "Level 5 autonomy", as defined, certainly wouldn't be the point where "it doesn't make sense to own cars".
Actual full autonomy requires many problems to be solved: General AI (strategy, parking, scene interpretation), sensors (blind driveways, convex mirror geometry, long-distance vision), as well as an infrastructure problem (interaction with authorities, emergency workers, etc). We don't have anything close to that General AI and 5 years isn't enough time to fully address/accommodate its shortcomings.