I think if you are organised having your ticket on your phone it is less likely to get lost.
My phone is waterproof, have you ever seen a traditional ticket after being caught out in a downpour?
My railcard is also on my pnone, everything in one place.
Full day out, I carry a small battery pack, or depending on what I am doing a full size several charges pack (which is about the same size as my phone and twice as thick). Nearly all long distance trains and a lot of local trains and buses have USB charging sockets, so if you are watching a video or playing a game plug in before your battery charge drops into the danger zone.
There are no queues at either the ticket office or machine to navigate and allow time for.
Some TOC apps seem better than others, I use Northern, which has proven pretty reliable, and TPE which is flaky, but I do get Nectar points until the end of the month with TPE, so from the 1st June TPE will not be used. I can use the northern app for tickets outside the Northern area.
I am in my mid 60s, yes there are a few people older than me who haven't taken to 'tech' but move forward another 10 years and paper tickets will be consigned to the history book. I dont know anyone amongst friends, family and colleagues who hasn't got a smartphone.