I have been very happy with DuckDuckGo, and it has helped me break free of routines that I did not feel safe with. Especially the small flame icon that would clear all history, cookies and cache from websites that are not "fireproofed" was great!
But today I had to do a quick example on Tinkercad (3D browser design tool) and it was so slow! I thought that my PC maybe was busy doing something (yeah its an older PC but not THAT old), but when I open the same page on my now parked Opera browser, everything went smoothly.
I am ok with using Opera, or any other browser for 3D work, as I don't really do all that much of it, but I just feel gutted to find out that my now favorite browser sucks so bad at something, not to mention the Microsoft Edge processes when that is the last of any browser that I would choose to use
EDIT: I found out that this was due to hardware acceleration was off, on my DuckDuckGo browser. I had turned it off, because the fonts on websites looked blurry when it was on. The solution was to turn off antialising on the Nvidia control panel, and restart the PC. It is now working well!
What I like with DDG is that I can clear all cookies, cache, history etc except for the sites that i have "fireproofed". Also all the tempting plugins that make life easier on FF are too tempting, and I always end up running many of them. The lack of such on DDG keeps things simple
I think you can whitelist websites to be exempt from deleting data from them on firefox too. I vaguely remember seeing something like that in settings near the "Clear Data" button.
On DDG it's an icon on the irl bar where I can just mark any website that I want it to remember. I them just torch everything else multiple times a day.
Also Cookie Autodelete is a firefox extension that allows you to whitelist websites you want to keep cookies for and auto delete the rest when you close the tab/window. I've been using it for like a decade on Firefox for my computer and phone.
I used to use the DDG app for quick searches on my phone from the widget because I also liked the fastness and auto torch everything on close feature, but then I discovered Firefox Focus. Essentially the same, but imo better in some ways particularly with the additional benefit of using Gecko instead of feeding the Chromium/Blink monopoly. And I can still use DDG as my search engine with it. Complete win for me.
In Firefox, you can use the cookie autodelete extension (it's open source) which deletes all cookies for sites you haven't explicitly whitelisted. Same thing, integrates well with other privacy features on Firefox (like container tabs and I still don't care about cookies, and is probably better maintained than the feature in DDG.
IMO starting with a more minimalistic base, and adding whatever features you need is a better approach that suits more use cases. Just reduce your extensions to what you really need, and deactivate or uninstall those you don't need. Make sure what you are installing is open source, well-maintained and trustworthy (look at the github page: when was the most recent commit or release? how many contributors and stars are there? It's not foolproof, but a good start and definitely beats closed source extensions). Having access to more extensions is not a bad thing.
EDIT: don't use I don't care about cookies as it was acquired by some shady companies. Use the independent fork called I still don't care about cookies instead.
About reducing useless extensions, please don't use nor recommend cookie autodelete and I don't care about cookies (which has been acquired by avast or some similar company iirc).
Firefox (and any other modern browser) has settings to delete website cookies on exit and to block third party cookies, while giving the ability to whitelist for both features.
For the annoying cookie popups just enable the adguard annoyances lists in ublock origin, which you already want to install on a browser anyways.
You are correct, I don't care about cookies was acquired by avast. It is still GPL3 licensed and, according to the privacy policy, does not capture user data. But for those who don't trust avast (which includes me), there is an independent fork called I still don't care about cookies. The builtin Firefox cookie deletion settings are not granular enough for my usecase (with container tabs) and a hassle to configure for imo, which is why I still recommend the forked extension if it suits your usecase.