What was the ultimate point of games downloading to HDD?

I'm just coming back into the gaming world once again because why not, right?

I just want to know, back in the ps2 days, you pop in the disc and call it a day, with a 8MB memory card.

Now we need 500 GB+ of memory because we need to download the games on top of having the CD.

Not trying to rant to much, just trying to catch up!

Games have improved graphics wise and their scope. The amount of detail that goes into games is insane and takes up a lot of space.

From my understanding, the hard-drive is capable of processing game content on much higher speed then the dvd/blu-ray lens, one of the reasons why you are required to install all PS4 games to the HDD. This practice has advantages, as for why do we need a disk in, that's simple, after it copies itself to your hard-drive - then it verifies that you have a legitimate copy of the game, when you start the game you will notice the game disk will spin for few seconds, it's basically making sure you have a correct game (and not pirated). After that procedure, the disk simply stays idle.

Therefore games are much larger in scope which requires large files to fill the hard-drive. On average around 40-45GB per game for PS4 and I believe that will increase to 60-70GB in next few years, plus you also have to count the patches as well. They can range from less then a 1GB upwards to 5-10GB depending on the game.

The good thing is, HDD are not too expensive to upgrade and it's a simple process. Hope that helps a bit with clarification, welcome back to gaming. :)