Many of you may reply to the title of this article with an abrupt "No," and prior to using the Canon 5D Mark IV for my own videos, I would have agreed with you. It's easy to judge this camera based on the specs because in all fairness they're not exactly groundbreaking, however, the 5D Mark IV might secretly be a great video camera.
I'm aware that many of us aren't particularly happy about the implementation of 4K video in this camera. The crop factor for one isn't great and it prevents me from using my full-frame lenses effectively. At a 1.74x crop factor, we're leaning almost into Micro Four Thirds territory and this it seems is a deal breaker for many, if not, most people. Not to mention the huge file sizes which use a bloated and outdated file format, meaning that the cost of storage increases significantly. There are however several redeeming features of this camera that more than make-up for its shortcomings. Eric Floberg, a photographer and YouTuber, discusses some of these features and reasons why the 5D Mark IV might actually be a fantastic option for many video shooters. For one the auto-focus system in the Canon is still the best system currently available.
Speaking as someone that uses the Sony a7R III regularly for video, the Canon is still much more effective and reliable for auto-focus. The implementation of tap to focus is also significantly better in the Canon vs the Sony and the touch screen works for all menu options too. The crop factor is a pain, however, using a good aps-c lens like the Sigma 18-35mm f1.8 pretty much negates this issue. Lastly, I really do love to look of DCI 4K, it not only has a more cinematic look to it but, works much better with smartphones and screens with wider aspect ratios.
Floberg describes some of the reasons why he thinks the 5D Mark IV is a really good video camera and I do agree with his points.