Gran Turismo Sport is extremely limited in offline mode

If servers or Internet are down, you’re stuck in “Arcade” mode with no saves.

Gran Turismo Sport review - Drive

Will Gt Sport's servers shutdown ? : r/granturismo

The Gran Turismo SPORT: Limited Edition includes: GT SPORT Game Disc and Collectible Steelbook Case GT Starter Pack (8 Cars) - Gain immediate access

Gran Turismo Sport - Limited Edition - PlayStation 4

Gran Turismo 7 NEEDS an OFFLINE mode!

Split screen multiplayer in GT7 is terribly disappointing. P2 is stuck with full assists, can't make the split horizontal so you're stuck racing on a tiny square, limited car selection, no custom

Gran Turismo 7 review: the updated verdict

Gran Turismo 7 Must Be Played Online For Virtually All Content - GameSpot

So, offline saving works in GT Sport now : r/ps4homebrew

What You Can Do in Gran Turismo Sport Single-Player When Servers are Offline - GameRevolution