On top of other important aspects that have been mentioned, another key reason why -especially very young- modern digital photographers want to use colour film and old cameras is that they have incorporated the many failures/shortcomings/quirks of aging film cameras, film, and improper exposure and development as a crucial component of their creative process.
Let that sink in for a moment if you're >60 years old and you were there when film photography was the only thing available.
Back then, if you were somewhat serious about your photography, you probably wanted squeaky clean images, hated grain, rejoiced at every new 'ultra-fine' grain Ektarish product that hit the market, sought to achieve only the very best exposure and demanded the very best processing.
This is not a goal anymore for many film photographers. They can obtain those squeaky clean documents with any phone, any time of the day, reproducibly - repeatedly.
People the age of your grandchildren, who are visual communicators in a way you are not (images must travel fast, to all corners of the world, to all people in a group of friends, now, not tomorrow via mailed print) don't want to give up the idea of sharing visual content via tiktok/etc but are fascinated by the idea of an old device introducing a number of artifacts on to the final image that have been widely accepted as desirable.
Why are they desirable? Not sure. A different thread. The randomness? The nostalgia? Maybe both and then some.
What are those features? I can think of a few on top of my head.
-The glowing halation of street lamps produced by Cinestill film etc. -> very much noticeable even from a scan
-Light leaks hitting the frame at random -> very much noticeable even from a scan
-Exaggerated noisiness caused by scanning a severely underexposed, perhaps overdeveloped negative -> a very recognisable look which is NATIVE to scanned C41 film
-Lens flare from poorly coated old lenses -> very much visible even on a scan.
-Unpredictable colour shifts from long expired, poorly preserved film -> very much sought after, and definitely noticeable even from a scan
-fungus/major dust problem in lens -> soft filter effect, very much visible even from a scan
-Shutter curtain issues, film advance issues, accidental double exposures -> all often considered desirable and part and parcel of an old, malfunctioning film camera and readily noticeable from a scan.
And so on and so forth.
'Yes but I can rEPRoDuCe ALL of that in Photoshop and Lightroom!!!"
The users I've described up here won't own Photoshop or Lightroom. They'll probably get a Macbook pro at uni in some years. Now all they have is a Steam Deck, a phone and an ipad to do 'homework'.
Those who are slightly older, and probably own a LR subscription, and probably own a DSLR of sorts, probably can't be arsed to try and simulate the above sitting at the computer. Why, if you can achieve the real thing with a small, interesting, old object and some film?
So film, scanned film, scanned film whose development and scanning is outsourced to a lab, gives many new adopters an opportunity to get images back with 'filters' preapplied by everything that happened upstream.