Hmm... I was actually considering a return to Firefox after learning yesterday of Google's embracing Manifest 3.0, which will severely cripple traditional Ad Blockers.
Very informative regarding Flash. So many sites still use it, as you pointed out, which makes for a frustrating experience. I also hate the bookmarking syncing feature and have it disabled.
I've used Chrome for years since IE is always more prone to hacking based on it's market share. I also love the Chrome Remote Desktop application. Since I use a projector with my HTPC, Remote Desktop allows me to handle basic HTPC maintenance [and disc ripping] using my tablet display instead...