We are so used to computer-generated special effects in films that we have become blasé about them. While producing these effects takes a lot of skill and tedious hard work, there is something about it being done on a computer that makes it seem to be not as clever somehow, though that does an injustice to all the programmers and artists who work so hard to produce these magical effects. We also know that the actors are not in any real danger, that they are safely on some sound stage in front of a green screen and that the dangerous effects are being produced in a studio.
It is nice to see how special effects were done in the old days before computers. You can see a compilation of some of them at this site from the era of silent films where the actors actually did many dangerous stunts but also faked others cleverly so that the audience could not tell the difference between what was real and what was not, and felt that the actors were in real danger. The compilation includes the famous one with
Buster Keaton Harold Lloyd hanging from the hands of a clock high above a street. They also had a clip of Buster Keaton riding a motorcycle over two moving trucks at exactly the right moment when they formed a bridge. Although this was a special effect where he was in little danger, Keaton actually did some of the other dangerous stunts that he appeared in, without any trickery.
For later special effects, here is how the scene with Fred Astaire dancing on the ceiling in the 1951 film Royal Wedding was done.
This article describes the special effects in 2001: A Space Odyssey (1968).