I live in Switzerland, and they don't use a tap in/tap out system at all. There are no barriers to enter the station, anywhere.
There are multiple ways to purchase a ticket, I usually use the app Fairtiq or the official SBB app, where I swipe right before boarding the train/tram/bus(it's a national system, so even works on the regional networks) and swipe left when I'm done with my travel.
It then calculates the best price for me. If I do multiple journeys, it will know what I should have gotten a 24 hour pass, and subsequent travel is free.
tap in/tap off sucks no matter how good the system is. It is fundamentally a wrong think.
I travel by public transport in many countries, I travel over the world for work, it is my preferred mode of transport. Switzerland has by far the best ideas. Luxembourg is great as well, totally free, but small.