IMO there's no normal or abnormal regarding this subject. Just more convenient or less convenient. For me, purchasing tickets in the app is more more convenient and efficient. When I used to take Greyhound to go to our timeshare in Atlantic City (sans my husband), I'd have to go to New York Port Authority. Drag my suitcase down to the main level, stand in line and buy tickets, then take an escalator to go downstairs. I no longer take Greyhound but not having to take the extra steps of going to three different floors would have made things a lot easier.
Now I take the train to Hoboken, N.J. I found out the hard way that trying to buy a ticket from the kiosk that was out in the sun and not functioning properly was not the way to go. I could hardly see the screen. Then realized it wasn't working anyway after fiddling with it. Buying the ticket on the train usually would cost more but I explained to the conductor that the kiosk wasn't working. Again, buying a ticket via the N.J. Transit app is so much more convenient. Even bus tickets can be purchased that way now. Same for the convenience of purchasing Amtrak tickets.