Well, I can totally see why you would feel that way but IT is actually 80s not 70s, and also was a made for TV movie. It’s pretty cheesy (the remake was better imo).

The Shining had a big budget and a big star and one of the best directors of all time. It’s almost more of an art film than anything.

Try it and see! I think it aged well but I’m old so my perspective is different. Would be interested to hear how it plays to a young person today!

My only advice would be if you do watch it, try to give it your full attention and allow yourself to be immersed.