The G in Gmail was for a gigabyte and that was what I got in the noughties for "free", when as you say my ISP offered something like 5MB on the end of a POP connection.

To be fair you can cram a lot of ASCII into 5MB. However you can email piccies to a mailbox with a 1GB limit if your modem doesn't melt first.

Obviously, this was during the "don't be evil" days.