In which case you get more disks. It's not as if storage is that expensive these days.

Shrinking is a short term solution, not a long term one. Databases tend to grow. Shrinking a database that is going to get new data is just going to force a grow, possibly at a time where that grow will affect users on the system, possibly causing external (file level) fragmentation. Reindexing to fix the fragmentation thatthe shrink caused is also going to force a grow.

The only time I recommend a shrink is after an archive and purge of data (in which case there will be lots of space free that may not be reused for months or longer) or when transfering a database down to dev with just a fragment of the data