All of us know two motives/needs were removed for TS3. Those were the room score/environment and the comfort score.
What if Sims no longer needed to actually eat, bathe or sleep?
Along with wishes/moodlets would be new buffs. A moodlet received if you made them take a bath..but no longer a motive needing to be fullfilled.
No longer needing to eat but receive a buff if your Sim ate certain foods.
A buff if a Sim received energy from a bed, couch etc. but no longer actually having to sleep.
Would you like that in the game?
With no longer needing to fill motives but just getting good buffs or bad moodlets if the player chose to make them use objects (but not necessary) a player would be able to play a Sim without being interrupted by Needs.
This is how TSM was coded in one area. Well, actually a few areas in motives.
Instead of a need to take a bath, the player could make them take a bath but not necessary anymore, or preen in front of a mirror to receive good buffs or could be avoided altogether.
Buffs were used in TSM to also fullfill a fatal flaw such as a drunkard needed to have a drink now and then..but the good buff (after having ale or wine drink) filled hunger, too.
But this could be reprogrammed for TS4 in such a way Sims no longer needed to eat but just receive good buffs if the player wanted to raise their mood with more buffs for eating a food they liked or that was a better dish than say fish stew.
Would you like TS4 if it no longer has needs/motives?
ETA: Btw, I know nothing about TS4, but this could be how it is played in the next series since this freed up the Sim in TSM and a new way of thinking about motives.
"Games Are Not The Place To Tell Stories, Games Are Meant To Let People Tell Their Own Stories"...Will Wright.