I loved how vacuum tubes were used in Thimbleweed Park. Every not working thing just needed the right vacuum tube.

Guitar pedals and amps would be one example of a place where tubes are still used. Audio or RF amplifiers, etc. Honestly the wikipedia page isn't that bad: https://en.wikipedia.org/wiki/Vacuum_tube#Vacuum_tubes_in_the_21st_century The transistor largely replaced vacuum tubes.

And it's not that they aren't made anymore, they're just not made in the quantity and variety they used to be. You can find auctions on ebay where there are random assortments of tubes that are probably part of some estate sale. If you know the numbers you can get a picture of the person's life: some tubes for ham radio person, some for audiophiles, but carefully curated and held onto until the end, just in case.

audio tech sounds better with vacuum tubes