Indies unite
That's a grossly ignorant and incorrect childish statement to make. Most PC games from the 2000's can also still be played like Mechcommander 2 and Half Life 2/Garrysmod. If you are talking 2010's games you are mostly correct because of the rise of "live service" games that are designed to brick themselves the moment servers go down.
It begins around 2006ish
Examples of physical games I have that are now broken.
Battlefield 2042 won't accept registration because servers shut. Completely unplayable without hacking work arounds
Bioshock 1 windows live. Shutdown disc doesn't work not redeemable for steam key. Completely unplayable
Dragon Age 2 physical disc is tied to Origin account. Non transferable to another computer. Origin store offline. 1 time registration completely unplayable
Morrowind Ubisoft re-release GOTY. Requires steam key but no longer runs on specified systems due to client shutdown. Effectively destroys the game when the original release still works fine.
Might & Magic X. Ubisoft Uplay servers shut. Unable to launch game. Although I heard this was rectified but it doesn't support operating systems the game was made for.
Rome Total war Mac Port. As an honourable mention game still runs but online patches at Feral interactive is shutdown.
Dead space 2 and Mass effect 3 are also tied to SECUROM DRM so if you bought the game over a decade ago like I did and had a few different computers since then, one day sooner than you think, you will get a popup saying your CD key doesn't work anymore for no real reason.
Though those games came out in 2011 and 2012 and are still playable even though EA has tried to remove the original Mass Effect Trilogy and Trilogy bundle from all store fronts in favor of the "legendary edition" that outright removes the co-op horde mode that Mass Effect 3 is loved for. Which servers are still up for too.
At this stage I am incredibly sceptical of services like Steam due to the fact they have games in the library they no longer work on Windows 10. The minimum requirements are stated on the site for operating systems that can't even access steam. I know when you try download a 32bit Mac game it has an error stating you need a 32bit launcher client. The last 32bit supported system was 10.14 (Mojave) from late 2018. Steam has already dropped support for this system in February giving the operating system less than 5 and half years of lifespan. Not to mention in the not too distant future they will drop windows 10 support so that renders half the library useless. An example of this is 'Medieval Total War 1' on Steam it doesn't run well past windows XP yet it's still available on steam albeit with scathing bug reports and compatibility reviews. Lots of thumbs down reviews. I've actually uploaded a workaround patch here on itch.io to fix the broken steam version. It's practically a crime in my eyes. I'm a plumber by trade and I cant just click my fingers and decide the warranty on my workmanship is void because it suits me. I can't bend the rules and regulations to suit my agenda or I'll have my licence revoked. It's no different to buying a car that self destructs a after 5 or 10 years. It's ridiculous