Nostalgia yes. And also utility. Icons have to scale both now and back then. Yet back then you had to draw pixel at a time or it looked like mud. Now you can do

Nostalgia yes. And also utility. Icons have to scale both now and back then. Yet back then you had to draw pixel at a time or it looked like mud. Now you can downsample and most will never see anything smaller than 128x128. Still sucks for users if they only see it rendered at half that size for menu or a reduced size taskbar. Or if it relies on color contrast without consideration for color blindness. Some designers aren't thoughtful enough to check.