Crikey, I can't imagine never using apps and emails.
Tickets - nothing I have booked in recent years posts tickets out any more. If I go to the local cinema my booked tickets are emailed to me and I need to show them the QR code.
I am a member of a charity and we communicate via email and WhatsApp
I am a member of another group that meets regularly and meetings are arranged via email
Our utilities supplier, building societies, bank, HMRC all communicate via email
Hotel bookings, holidays and other travel is always confirmed via email
Orders are confirmed via email. I can track them and make sure I am in to receive them
My hobby group communicates via WhatsApp
I have various store cards as apps on my phone - Tesco, Sparks, Boots etc. Takes up much less room than a bulging wallet
I use the Trainline to buy train tickets. I also have my railcard on my Trainline app
Not using apps and emails would definitely make my life more difficult and very small