Depends very broadly on your area of interest, but to throw out some random numbers and thoughts:
If you want to move data between two points, 30MHz of "bandwidth", depending on noise and signal, can be on the order of 30MB/s data rates or more assuming you're good at doing QAM or similar modulation. That's 50x what the CC1101 in the flipper maxes out at
If you want to search for a particular signal of interest (ie why does turning on my LED lamp open my garage door), that's more spectrum you can view at once, about 3x wider than what an RTL-SDR can receive. Similarly, you can view the entirety of a 30MHz wide emission as opposed to only seeing pieces of it.
You could monitor two different narrow bandwidth signal sources that are within ~30MHz of each other simultaneously, ie the 101.5FM broadcast channel and 121.5 airband guard channel. This provides the capabilities of something like a police radio scanner, covering the entire VHF or UHF land mobile band but without having to stop listening to find another signal and the ability to record the entire spectrum capture to disk so you can review all concurrent transmissions separately at a later time.
https://en.wikipedia.org/wiki/Waterfall_plot#/media/File:SDR...
Above is a spectrum plot of an FM broadcast station using wide FM modulation and with some digital sub carriers on either side for song info etc. Other stations will be to the left and right of it and the "bandwidth" of the receiver determines how wide the plot you can view is.
