Better to have full cars using the roads and all of the otherwise solo drivers in their largely empty cars attracted to public transport.

There'll be various reasons why a large family can't take a train, but drastically fewer reasons why a person or a commuter travelling alone cannot (or, a group of friends, or a couple, etc.)

Maybe one day that'll change again, but at least now it helps reduce the amount of pointless traffic on the road.

Do you actually live in Austria? Because I've seen comments about family tickets. I only know Switzerland - where your kids under 6yo will travel with you for free and your under 16yo half price.

Kids under 6 are free on almost all public transport in Austria.

For older kids there are a lot of discounts, but many of them are only cheap if you use public transport regularly. (eg. rail card family from the ÖBB for 19€ a year, or upper austria regional tickets for school children for 77€ a year, etc.)

One problem is that it's not just train tickets, but you also need tickets for bus/tram/subway, and every city/region has different systems, so for every trip I spend about 15min trying to figure out which tickets to buy.

Well at least in CH you only have one ticket for everything (yes including regional rail providers, buses, ships, even many cable cars), so maybe AT could follow the idea. Plus you have that nice little feat called "EasyRide" (initially from a startup) where you enter that you start the ride and who accompanies you, and it will compute your final ticket costs only when you say "checkout". 90% of the cases it comes cheaper than I would have thought when buying the tickets by myself (the rest 10% of time the price is the same as estimated)