Pick up the base game for the low, low price of $0 and keep it forever.
The Sims 4

EA and Maxis just made the entirety of the base game of The Sims 4 totally free to download. This free offer doesn't seem to have any sort of an end date and it applies to all platforms: PC, PlayStation 4, PlayStation 5, Xbox One, and Xbox Series X|S.

The Sims 4 is now eight-years old at this point. It also has a ton of DLC releases and expansions. Fortunately, a lot of those expansion packs are currently on sale. You can find these sales going on through storefronts like Steam and others.

If you already owned The Sims 4 prior to today, you will be given the Desert Luxe Kit for free.

"EA and Maxis have welcomed millions of The Sims players over the years. With The Sims 4 base game going free, the team is more dedicated than ever to developing new and meaningful experiences for players, and will continue to develop and release packs, Kits and Sims Delivery Express drops into the foreseeable future."
As far as the future of the Sims is concerned, Maxis announced something called "Project Rene." The name, Rene, was selected to invoke thoughts of renewal and rebirth. Maxis wants this "to represent the developer's renewed commitment for The Sim's bright future."

Project Rene is still very, very early in development. This means whatever it ends up being won't be released for several more years. The studio did show off some cool new features that weren't previously possible in the older Sims titles. One feature shown off includes the ability to deeply customize the look of a bed, from its bedspread color and pattern, the look of the footboard, and more. A similar degree of customization was also shown off for a sofa, where individual cushions could be customized by way of shape, design, pattern, and color.

Project Rene seems like it will be playable on multiple devices. One demonstration saw a game file copied on both PC and mobile devices.

"Today marks the start of our journey over the next few years as we work on this next game and creative platform, currently titled Project Rene. We are building on the same foundation that has made The Sims compelling for generations of players and pushing the boundaries to create new experiences. We’ll have much more to share as we continue to progress on the game’s development and milestones along the way."
As of right now, there is no saying whether or not Project Rene will end up being called The Sims 5 or simply The Sims or even something like Sims. With this idea of a "rebirth" going on, I wouldn't be surprised if they sort of "relaunch" the franchise again.