As for why Electronic Arts will not be releasing The Sims 5, this is so that players who have spent the past decade on their The Sims 4 save files or game will be able to continue doing so.
::
The Sims 4 players will continue to see new updates, including paid expansions and packs.
::
While it will be possible to play with friends, it will not be an MMO like The Sims Online was.
::
Instead, it will continue to release updates for The Sims 4.