Also, GTA IV was so boring compared to it's predecessors. A typical budget phone (SD720/30 with 3-4 GB RAM) would probably not run it very well, depending on how well the port is done. Then IV at a later stage when even budget phones can run it at decent settings. However, I'm sure Rockstar wants to make profits for remastered I, II and III first. Not to mention just how much faster the RAM of smartphones is (LPDDR5).
The RAM requirements were also low, so most smartphones today have plenty of RAM and RAM to spare as VRAM for the GPU seeing as it's shared. Obviously for higher performance a 512MB was recommended, but still no more demanding than cards older than the GTX-lineup, like the 8*000-series from nVidia, could run it at high performance 13 years ago. Even cards like NVIDIA 7900+ and ATI X1900+ could run it. Can they run old games like GTA IV and V? Yes, they can. Laptops, and their APUs, aren't that powerful vs smartphones as far as graphics performance goes. Just like laptops have as part of their APU if not running discrete. moreSmartphones does have GPU as part of their SoC.
Bruh, No Lol GTA 5 can't run on Mobile neither GTA IV.