Yes, most of it works fine but when it doesn't:
- the AC stops working, the windows don't open and it gets real hot real fast
- unless it's some extreme situation they will not let you leave the train
- you're stuck in the middle of nowhere, with no infrastructure in sight
- it's really hard to get you to alternative transport
- fixing the issue can take hours
With a car:
- you can get outside
- you will have to wait 30-60 minutes to get towed
You see multiple news every day about trains in Spain,Poland or Germany with broken AC or just completely failing between stations.