I created simple elevator blocks for 1.21.4. They come with settings and can be disguised as any block.

Yes, this is survival friendly and available as a download: https://modrinth.com/datapack/vanilla-elevators

Edit: finally managed to add the video. Didn't understand the error message "too many frames". Luckily my phone gave me a more readable error ("max 1 minute video) so I knew I had to speed up the video a bit.