The immediate benefits of these particular improvements are quite easy to grasp. Your next Bluetooth speaker shouldn't stutter when you accidentally take your phone with you into the kitchen, for example, and your next smartwatch should receive those push notifications that bit quicker, thanks to more bandwidth for data transfer. This becomes a lot more important when internet of things devices and Bluetooth beacons enter the conversation, though.
Bluetooth devices that broadcast information, as opposed to the kind you pair with, are becoming much more common, independent and easier to communicate with. Bluetooth 5 increases broadcasting capacity eight-fold, meaning much more data can be sent (and received) in a single interaction. Instead of a Bluetooth beacon pinging your phone with an URL that then gives you more info on a museum exhibit, for instance, it could do that and pinpoint your indoor location... and send you a discount voucher for the gift shop, all in the one blast.
The Bluetooth SIG isn't in the business of dreaming up specific applications for the technology, though. Instead, it's interested in improving things like range and data capacity, and letting everyone else dream up the new applications and connected devices.