A big reason why old games aren't buggy is because people only ever consider the good games. If you start considering older titles that where average and under not only do you get bugs, but they can get pretty bad. Donkey Kong for the N64 was a good game, but ran into a memory problem forcing Nintendo to include memory packs with the game to give the N64 enough RAM to run it properly. An old game I played called Tak would have bugs where the character would get. In half life you could "prop surf" by sticking one item under another and lifting up to fly from the collision.
I mean even considering a game like Morrowind as an example. Bethesda had a memory leak in the game when they ported it over to Xbox, but found an extra sneaky way of fixing that: rebooting the console. The OG Xbox had a weird quirk in that you could reboot the console whilst holding a load screen.
Modern games got a lot more, even the smallest details can have really big bugs. Facial animations track eyes, micro movements of the muscles, teeth, tongue, hair to a high level of detail whilst older games would just have the lips flap in a vague way to convey they are talking. Physics used to at most allow an object to drop straight down to the floor, but now it calculated impact position, ground material, weapon shape, bounce properties, collision sounds, and in more advanced case dirt and debri. Your reload used to be a 2d animated sprite, but is now a 3D model that has different animation for reloading a full or empty gun, with a sound playing each time your reload animation touches a mechanism on the weapon.
It is made worse by companies realising they can skip a lot of the bug testing in favour of making the day one players test the game. Worse companies are of course a lot guiltier of this crime like EA, and the such. However there is a point where it starts to get unfeasible, even for the best companies to hunt every bug. Especially with how big games are now. A single borked animation, a single flag set incorrectly, a single memory management bug can cause a lot of issues that isn't found until you have a lot of players exploring the world.
I mean even considering a game like Morrowind as an example. Bethesda had a memory leak in the game when they ported it over to Xbox, but found an extra sneaky way of fixing that: rebooting the console. The OG Xbox had a weird quirk in that you could reboot the console whilst holding a load screen.
Modern games got a lot more, even the smallest details can have really big bugs. Facial animations track eyes, micro movements of the muscles, teeth, tongue, hair to a high level of detail whilst older games would just have the lips flap in a vague way to convey they are talking. Physics used to at most allow an object to drop straight down to the floor, but now it calculated impact position, ground material, weapon shape, bounce properties, collision sounds, and in more advanced case dirt and debri. Your reload used to be a 2d animated sprite, but is now a 3D model that has different animation for reloading a full or empty gun, with a sound playing each time your reload animation touches a mechanism on the weapon.
It is made worse by companies realising they can skip a lot of the bug testing in favour of making the day one players test the game. Worse companies are of course a lot guiltier of this crime like EA, and the such. However there is a point where it starts to get unfeasible, even for the best companies to hunt every bug. Especially with how big games are now. A single borked animation, a single flag set incorrectly, a single memory management bug can cause a lot of issues that isn't found until you have a lot of players exploring the world.
