PS2 has "bad sectors" pressed into the disc. Their DVDs are not BURNT, they are made with glass masters. Burners do not have the technology to make these bad sectors the same way the glass masters do..... so basically until somebody is able to figure out how to TRICK theplaystation, 1:1 copies won't ever be happening.
in the meantime, you can backup the PS2 game for everything except those bad sectors, and a mod chip or swap disc or many other things wil llet you play them.
it is illegal to do this with any games you do not own.