When you encounter an actual vintage site that has been online since the '90's, that's sometimes the only thing that breaks :) There were no other dependencies

When you encounter an actual vintage site that has been online since the '90's, that's sometimes the only thing that breaks :) There were no other dependencies. Looks like the characteristic error message puts the final realistic touch on what the real thing looks like any more :) How complete will today's websites render 30 years from now?