Kodi is an impressive open source home entertainment platform that is very easy to use, free, powerful and flexible. You can spend endless hours streaming TV, movies, sports, music and many other contents via Kodi.
The problems are:
1) Security: There are a lot of anonymous third-parties contributors that develop Kodi addons. There are no guarantees those addons are "clean and friendly".
2) Privacy: Your ISP (Internet Service Provider) knows that you are watching tons of pay-TV for free and that is a real cause of concern.
3) Live TV and sport channels are commonly blocked based on geo-location and you are unable to stream the content.