It's also hella buggy on macOS for me, which is irritating - my browser is the only thing I need to work 100% of the time. As much as I'd like to reduce Google's browser monopoly, I consciously choose to make this one exception.
Any particular bugs that are annoying you? The main one for most people seems to be excessive battery consumption on retina displays, which is being worked on (requires switching the renderer interface over to Core Animation, so is understandably taking a while). Apart from that I can only think of minor annoyances compared to some of the problems with Chrome like major memory consumption and the gradual strangling of personal privacy extensions.
In my experience, watching videos (YouTube, Twitch, etc.) for longer than a few minutes frequently causes Firefox to overload my CPU and bring my entire system to a crawl.
That is the only major issue I have with Firefox. I still use it as my main browser. For one thing, container tabs are a killer feature.
I don't think most experience what you do with video in Firefox, I wonder if you have hardware acceleration disabled.
I was interested in Firefox containers but quickly lost interest when I discovered Firefox Sync doesn't sync container configurations, I wasn't going to replicate them in multiple places.
I had to switch to Chrome after Firefox caused my computer (macOS Mojave, 2012 MBP Retina) to freeze to the degree of requiring restart every few days. Even when it didn’t freeze the entire machine, the browser itself would lock up a few times a day. During the course of normal use, my CPU temps would jump to 100°+ from a baseline of ~55°. (And battery life was disappointing, as other comments have noted.)
These issues occurred when my computer was plugged into a charger or on battery power. Replacing the thermal compound, thoroughly cleaning the fans, and reducing the number of open tabs and windows didn’t resolve this. Chrome doesn’t appear to cause these issues on my machine, holding all other workload and plugins constant.
I really want to use Firefox but cannot rely on it currently.
Add-on context menus display only when launching them through overflow menu, it doesn't work when I put the icon next to the navbar.
I have a smaller DPI non-retina MBP2012 and I always set the default page size to 80% in Chrome. I used two extensions for the same functionality in Firefox (Fixed Zoom and a second one that worked a bit better) but I always had issues with the sites being bigger than the viewport and having to scroll around them to see the content. Images were the biggest victim to this behaviour.
You are right - there are issues in Chrome, but I don't feel them as much in my day to day life and it counts for me.
Firefox has some better plugins and features, like container tabs. You can block ads with the built-in tracking protection, uBlock Origin (not uBlock), and uMatrix.