1 Eleven: Fine. I’ll open the secret door with my “magic powers”.
2 Eleven: There. Ugh, my nose is bleeding again from the effort.
3 Eleven: There better not be anything else in this tomb that can only be resolved through magic.
4 Dustin: Do not tell her about the ochre jelly!
4 Lucas: Or the spike pit.
4 Dustin: Or the demi-lich!

There's a lot of stuff on the original Tomb of Horrors adventure with specific caveats such as "this cannot be opened by any other means except magic" or "this cannot be detected by any magical means". It kind of straitjackets the players into single solutions to what would normally have multiple different possible approaches.

This is not great adventure design, by modern standards. It was a bit more understandable in the context of the day, because Tomb of Horrors was written as a tournament adventure, and they wanted an adventure that was more objective in some way to allow a scoring and ranking system for players. Rather than allow anyone to proceed through an obstacle by using creative means, this rewarded the players who puzzled it out and discovered the expected solution.