I agree with you here.
Many are not yet at the level they COULD be - for what reasons one could only surmise. But when we are told to be perfect, even as our Father in Heaven is, it appears to indicate a journey to that goal, other than an instaneous transformation to that plateau.
Uh uh Uhhhh.
The only reason you speculate any such "journey" is your understanding that you can't perform what is commanded. You're letting your experience cloud your understanding of what the text clearly says. I'm not aware of anything that Christ said that temporizes His clear statements in Matthew 5 and 6. The difference between us is I have no qualms about admitting there is obviously more in play than a cursory reading would indicate..