Former Rockstar technical director Obbe Vermeij says that stealth missions were something the team regretted about GTA San Andreas.
Over on Twitter, a fan asked Vermeij about a silenced M9 Beretta pistol found in the files of GTA 4, as well as two apparently cut missions featuring scripted stealth mechanics. The former Rockstar dev says that while "I don't know about the 2 missions," he explains, "My recollection is that stealth was specifically one of the things we regretted adding to [San Andreas] as we ended up stretching ourselves too thin. So I thought stealth was never pursued in GTA4."
I don't know about the 2 missions. My recollection is that stealth was specifically one of the things we regretted adding to SA as we ended up stretching ourselves too thin. So I thought stealth was never pursued in gta4. Then again, there were experiments going on all the time…June 3, 2026
However, he doesn't deny that it was possibly in the game at some point, adding "there were experiments going on all the time that I didn't know about." GTA 4 was already a pretty dense game by the time it came out, and over the years, a number of cut things or other rumors have emerged, such as a ferry that was "ditched" as well as a rumor about GTA 4 getting zombies, which Vermeij previously said was "probably an experiment that didn't work out."
Granted, Vermeij also said previously that he "didn’t like GTA 4 that much" at launch because "we had to sacrifice so much in terms of gameplay," so while he was probably happy to see the back of stealth, it may have been something that was cut in pursuit of the game's more realistic tone compared to San Andreas and 5.
Saying that, GTA 5 did have some stealthy missions, such as stealing cars for Simeon, and a number of missions featured in GTA Online. Not to mention some of the heists can be done somewhat quietly (at first, transporting a vault isn't really stealthy). So there's a chance that Rockstar's experiments went into the development of GTA 5.