Modern vs. Vintage CD-Rs

I’m starting to go down a rabbit hole trying to burn and read CD-Rs on a variety of modern and vintage equipment, and it dawned on me; are all CD-Rs created the same? Is a CD-R manufactured in past year somehow different from one made 25 years ago? I’ve been able to burn modern CD-Rs on my LG DVD drive, my Apple usb SuperDrive, and a 2008 iMac, but not on my 2000 iMac nor my Lacie FireWire cd drive. Similarly, CDs burned on modern devices are inconsistently readable on older equipment. Trying to isolate all the variables to getting CD-Rs consistently burn and read has been vexing.