Yes you are correct. So you can see I was shocked at how people came to this thread and cried "troll" without even reading and understanding what I was trying to say,.
Another reason these games are graphically inferior and requires low end hardware is for online population. If a game has millions of players online, it will attract Millions More because then things such as proper match making becomes a reality. No need to alter the algorithms and put you against players of way different levels. You can actually be placed against players of your same skill.
Therefore giving players what they want, people want a solid functioning game that has good gameplay, proper netcode and is fun and addictive. Also something to note Blizzard and Valve focuses on "artwork" rather than ubber realism
This is why no matter how old some of these games get they always seem to look great, a good artist is better than a architectural designer making real life stuff in Unreal Engine 4. Most prefer an art direction rather than realism, it gives video games the "magical feeling" it always was about.
These 20 year games and 20 year CPUs is regarding the 90% of PC Gamers. The thing though is the motherboard will die before you even get to 20 years but I was just drawing reference on how a CPU can last 20 years and play games for 20 years for 90% of PC Gamers. A 4790K i7 will last 20 years easy at this point we are in, tech is mature now to that point.
The huge issue is people compare 2015 tech to 1995 tech and they fail hard at doing so. Tech now, the stage it has reached and the yearly increase it gets, the games we play today, the microtransaction and free to play business model, the wide popularity of the internet today is nothing remotely close to what you would have had in the golden age of 1995.