I have been using bitcoin to buy things for the past 3 years. I only use fiat for food/petrol/rent but the person I pay rent to has started accepting bitcoin and said they will allow me to pay in it so they can keep it as an invesment. The lady I rent from is clever like that.

Anyway here is a short list of somethings I have bought with bitcoin just so you have an idea.

Video games (lots of these)
An entire pc+eth mining rig
Gardening supplies
Cannabis seeds
Cellphone airtime
Netflix giftcard
Google giftcard
Online subscriptions to adult entertainment sites as well as exclusive forums.
Electronic equipement
Electric plugs/adaptors
Lights/Led
Airbrush kit and paints
Arts & crafts supplies
Figures
Software
Shoes
Certain brands of clothing from certain online stores


There is much much more, these are all online and deliver to my house. There is also a mining store where you can buy coffee and tea and treats for various crypto. It is the only physical place you can walk in and spend bitcoin.