You can fit text-only wikipedia on a normal Blu Ray as it's only about 24GB. You can also easily fit Llama 3.1 or any of the other open, offline capable ai models as they're only about 4GB.

could also store it on a flashdrive or micro sd card

Can you give me the text only version link? I found only a version that is like 43gb

500TB is still surprisingly reasonable for what is essentially a library of human (surface level) knowledge.

It would be interesting to know how large the file would be including all text form references (i'd imagine anything else such as videos would completely blow the proportions)

So gonna need like 2 CDs then

yes you really can; it's like 20-25 gb depending on how recent of a copy you have. I've been seeding wikipedia for almost a year and it barely takes any space on my computer