The first downside can be the loss of support and warranty from apple. The warranty is probably not an issue for an iPhone X. The biggest risk of jailbreaking is that it eliminates security protections provided in the OS so the entire phone and its content is accessible by virtually any app on the device. This could expose all manner of information. I have no idea how common penetration of jailbroken iPhones is so cannot give any advice about the security risk other than to say that you would be increasing risk and potential exposure. There are articles online such as this one, Jailbreaking your iPhone: Worth the security risk?, which give a bit of an idea.
Thanks for the info, namely some of the media streaming apps like ESPN and Netflix so I can watch on the information screen. I have a work around that I can use it through the HDMI port and the adapter to the lightning cable but I was trying to get rid of the cables.
