QTBrowser's is easy to setting up, you don't need to edit the config, like in Firefox(Otter Browser has extanded functions, in about:config), to delete spyware (QTBrowser's don't have spyware functions), or show hidden functions. I use Qutebrowser, and it's have active community on Reddit, where you can find help.
QTWebEngin is based on Chromium Engine (Blink), and this is good, because for today, Google - is leader in Web Browser, and most of sites work best with Blink.
All of the famous QTBrowser's have built-in AdBlock, who can work with ADB lists. yes, it's can't be goodest, than uBlock Origin, but it's too not bad.
QTBrowser's have built-in proxy, and it's good, because Firefox browsers don't have it, and need to install extansions (It's possible, because Chromium have this function).
You can change mostly, of the interface elements. You can edit toolbar, edit default font's, change panel's position, install custom themes, or just disable all interface element's, and focus only on page.
You have possablility, to built-in you script, and use it. As example, i make a redirect to free front-end of the popular sites, like Invidious, and Libreddit. Also, you can use GreaseMonkey scripts, who have active community, and script's database on OpenuserJS.
1. Don't have good JS-blocker's
QTBrowser's don't have extansions like uMatrix, it can only disable JS on all sites, or enable it, where it need, and give some permisstion's limit to JS.
If you want to translate, or add something, you can make commit on my Codeberg repository. Thank's for reading me and help!