All the Reasons Why you Should get the 80D instead of the 77D (80D vs 77D)https://www.youtube.com/watch?v=dG935usQTy0

The 80D is a larger camera that feels nicer in hand for most people and balances better with some longer lenses
Bigger battery, almost a 1,000 shots per charge - almost double what you get with the 77D
80D offers a pentaprism viewfinder vs the 77Ds pentamirror this means a bigger brighter view of the world, especially helpful in shooting in lower light.
80D offers larger rear dial, slots to assign custom settings on the mode dial and a dedicated AF-On button
80D has a headphone jack
80D is weather sealed.

80D offers a faster top shutter speed of 1/8000 of a second vs 1/4000 on the 77D - This isn’t about photographing hummingbirds - this is about being able to shoot with fast prime lens outside - being able to go above 1/4000 makes it easier. Will you need this? Do you plan to do portraiture with fast primes outside?
On the 80D You can also adjust ISO at 1/3 increments vs 1/2 stops on the 77D
80D offers Micro Adjust autofocus - this allows you to calibrate your camera to the lenses you are shooting with to get the most accurate focus and sharpest images
80D shoots +7 fps vs 6fps in the 77D - it’s a small distinction but one that could make the difference in catching the perfect moment when shooting faster action like sports.

To be fair there are a few reasons you may want to buy the 77D

77D(9000D) comes in a smaller, lighter body that you can purchase at a cheaper price
77D(9000D) offers an updated interface that beginners might find useful
77D(9000D) offers electronic stabilization for video - honestly I am not terribly excited about this method of stabilization it is just OK and certainly doesn’t smooth out larger movements like the stabilization offered by Sony, Olympus and Panasonic AND only works during video.