As a software developer i can say it is not a feature as they want to sell it to us. They simply not want or not allowed to change the game code to do a proper way to handle multiple instances of inventory (normal and ventures for example) and other data.
Since battle royale came we only got surface changes. Failed to lock profile is a workaround at surface level to make sure profile data is ok. Again, it is a workaround and not a real solution. My guess is that when something changed at save the world, further battle royale tests needs to make sure there is are side-effects, as we saw a lot of side effects from battle royale changes in save the world.
If i would come up with a smiliar "solution" to a problem at my work my boss would probably say something like "you have 3 days to solve it properly or goodbye" and i am not working for a billion dollar company.
P.S.: I believe the devs are not allowed to fix the problem, this topics is not against them. More likely we have to hear our voices to finnally make epic allow them to fix.
Source: https://www.reddit.com/r/FORTnITE/comments/o424kw/failed_to_lock_profile_is_not_a_feature_but_a_bug/
