When it comes to Microsoft Edge...I want them to spy on me because I want them to know that I use linux.
Firefox seems all right but it is the complete opposite of Vivaldi. Vivaldi is much configurable than any other browser. In fact, Vivaldi is so much different than any other chromium browser (except for Opera, where it seems to have some similarities) that it has been successful in creating an identity of it's own much less like Edge which looks like a reskinned google chrome.
Firefox on the other hand is not configurable at all and most of the configurations are possible only due to "addons" just like GNOME. Although it doesn't affect usability much, it does hamper the workflow, when you can't configure the browser like you want it to be. Moreover, you can't do a simple image search which comes in handy when you are looking for original source of an image or trying to extract wallpapers from screenshots of other people's desktops (yes, I do that). You can't even set a background in Firefox and when you use an addon to get a nice looking new tab page, it displays a banner kind of thing in the address bar naming the extension that manages the new tab page. I used to use Firefox before the chromium browsers and I liked it but then the frequent full point releases and the constant UI changes made me switch.
Now, I am addicted to Vivaldi. I tried using Brave, Edge, Chromium and gave Firefox few more chances but I found myself coming back to Vivaldi every time.