The Xbox 360 and PlayStation 3 had only 512MB of RAM. Features like the dynamic gang system and persistent fast-food interiors caused massive frame-rate drops.
In the case of GTA V, Beta 0.7 dates back to roughly late 2011 or early 2012. This was a time when Rockstar Games was transitioning from the gritty, grey aesthetic of Grand Theft Auto IV to the sun-drenched, saturated environment of Southern California. Major Cut Content and Differences gta v beta 0.7