It's never been "good", I played since 2013, Xbox 360 and later repurchased the game for PS4, the online load times were not just annoying they outright broke the game for me. To be having fun and then have a many minute delay while being pinned to the screen (because after loading from a mission you're never in a safe place).
Looking down on the ground through the clouds at the san Andreas's streets with that wispy air sound while waiting for those large thud noises which could come randomly will forever be etched into my memory as something which completely broke the fun I was having, especially when playing with friends and trying to do Heists later in the products life.
And because of this: getting people to play was really difficult, the combination of huge updates which took hours to download (PS4 has slow access to it's drive even if you upgrade to SSD) and the insanely long loading times once you have the patch culminated in many hours of lost gameplay.
I remember a quote from Steve Jobs which fits here: "Let's say you can shave 10 seconds off of the boot time. Multiply that by five million users and thats 50 million seconds, every single day. Over a year, that's probably dozens of lifetimes. So if you make it boot ten seconds faster, you've saved a dozen lives. That's really worth it, don't you think?"[0]
[0]: https://www.folklore.org/StoryView.py?story=Saving_Lives.txt