There is a simple way to share Steam games with your friends so that they don’t need to pay (tested on BeamNG.Drive)
NOTE: Online features may not work
1. Go and find the game files of your Steam game (C://Program Files (x86)/Steam/steamapps/common/(name of game)) or just click on browse local files in Steam client
2. Now go 7zip the folder (https://7-zip.org). Go with max compression
3. Upload the 7zip to a large file sharing site (https://transferfile.io)
4. Send ur friend the link
5. Friend downloads it and unzips it
6. Now the friend needs to find the main executable of the game, he clicks on it and it opens up successfully