It absolutely does sound dated (has, errrr, ANYONE looked at the lyric sheet??) and yet it's timeless because the sound has become so iconic. It's not their fault, but I'm not sure Sabbath can be forgiven for the thousands of bands that tried to copy them who were shite vs. the only-hundreds of bands that copied them who were decent to good to great. The ratio is probably pretty typical in rock and roll but for my taste it's pretty imbalanced when it comes to "heavy metal".
Also once again we are going to have the "I'm not a Brit" problem complicated by the "I'm not quite as old as some of you" problem which means I have to look at this record in the context of what I like today, not how influential it was yesterday, and the devil and sorcery stuff turns me off. Way off.