Thanks for the detailed explanations.
What if I am the only player in those games that have sheer size of "worlds"? Is 9900K and RTX 2080Ti not enough to handle the sheer amount of calculations needed?
For sure it is, but that's a single-player environment. A home setup can even handle co-op based gaming. (like an open world RPG where it's you and a few friends in the party)
But to be able to handle the calcs for hundreds or thousands of players at once, you need lots of power.
It depends on the type of experience you want. The only real reason to play an online game, is to interact with real people, and if there's a large number of people available to interact with, a home PC won't cut it. Myself, I prefer singleplayer RPGs, because the storyline is usually more intimate and focussed.
I have seen many students playing League of Legend. It seems to be free of charge and does not require installation. There are also some advertisements for games that show up automatically on my browsers. Given that these games are similar to those commercially available games in the price range around $35-70, why spend that kind of money when similar games are available for free?
It really depends on the game, and how you like to play. If you play for free, you won't get all the content, but that may not matter, depending on the game design.
And again, it depends on the experience you want. If I'm in a competitive mood, I'll play an online PvP game. If I'm in a relaxed mood, I'll play a singleplayer game, where I can hit pause and go have a smoke, or make a sandwich if I feel like it.
The biggest thing pricewise though, is that, even though a game is free, (or especially if) there's going to be some form of enticement to pay. You may find, for example, that character advancement slows at a higher level, due to greater amounts of XP needed. Maintenance costs may rise to the point where a free player can only break even after a raid.
For example, I play World of Warships. I played for free the first 3 years, because advancement was reasonable, and I didn't care to purchase anything. Then I started getting higher tier ships, and my credit gain slowed to a crawl. So now, even though I still don't buy anything else, (they offer "premium" ships, some costing over $80) I pay $15 a month for a premium account, which increases my battle rewards by 50%, and puts my advancement back on track.
If you can play a free game completely free, thats's great. But it doesn't take long for many players to be spending a bit here and a bit there, and eventually enough to buy multiple games.
I do both, just because I like to have gameplay options. Sometimes I want to play online, knowing that I'm pitting myself against other humans, and sometimes I just want to sit back and immerse myself.