There's only been like 3 times mainly that have been found out about publicly at least
OnionDuke Malware (2014)
Operation Onymous (2014)
Tor Exit Node Malware Campaign (2020)
So it can happen but doesn't happen often and the people who pull it off usually have virtually unlimited funding to do it. For the common person its still safer than rawdogging the internet
Not really but due to the current US administration I think Europe is realizing they need more of their own autonomy back. That's why Germany and others are switching to open source options and I'm so glad to see it.