It's useful when you need to pass a values numbers to another study. Study-on-study (SOS) in Tradingview allows passing only one value, which is not always convinient. So if we put all those numbers in one - we can pass more values from one study to another.
In Pine we can use up to 52 bits for our data. Because of that we can put 6 1-byte (8-bit) values in one float. Or 12 4-bit values. Or 52 1-bit values.
Apart from passing output signals for buy/sell/close buy/close sell signals
Curious to know what are the general use cases you have in mind?