You didn't read very carefully. 1/I/i/L/l are all interpreted as 1, so it doesn't matter which one they are misreading it as.
Do you contest that l can be misread as 1 or I? Because that's what the table means. The code is case-insensitive.
I declare that 5 can be misread as S and yet there they are. (And that L looks like 1 or I far less frequently than 5 looks like S)
it's a1so very different in monospaced fonts where these
identifiers are 1ike1y to be read. 'l' 1ooks much more
1ike '1' in these fonts.