No.
> Even if they don't, you, the (power)user should be able to manually turn on whatever you want, should you so desire.
It's not as simple as that. As long as it is possible for extensions to have no-holds-barred access to your browser then they'll make that a condition of use, and unsophisticated users (approximately everyone) will just say "eh ok".
Browser extensions are a particularly dangerous case because they auto-update by default. It is very common for popular extensions to get sold to bad actors who then update them to inject ads into everything you view, or worse.
If you make it impossible for extensions to do that, then they can no longer make it a condition of installation.
Then make it complicated enough so the user has to click through several screens, type in that they know what they're doing and be warned that if extension/website X asks them to do Y, they're getting f'd and should stop. Beyond that, it's their fault.
Why can't we treat browsers like we used to treat PCs? Why do we have to have to make them so "safe" like we did with phones? Tons of scams happen on phones now, so it didn't quite work out, but we still gave up a lot.
Personally, I'm rarely a Chrome user. I'm most afraid of stuff not working in non-Chromium browsers, though.
Yeah I mean... that's just an arms race. You now have to type "allow pasting" into the dev console to paste Javascript there. Guess why.
Browsers can't ever win that race. Malicious extensions will just say "go to settings and blah blah blah".
Putting security in scare quotes doesn’t make the actual risk go away. This is a blatant anti ad block move, but you aren’t making reasonable arguments either.
One can find reasonable use cases for every security measure that takes away freedom. That doesn't mean that all such decisions are balanced, and I'm advocating that the user be the one deciding their level of security, knowingly. That's the most important part being taken away, actually. Until there's palpable resistance (or even doubt or endless debate), those taking things away have no reason to stop.
As to your security argument: If you've never seen the past user's desktops filled with browser hijacking and ad / virus ware, then I'm happy for you, but ignoring serious security concerns isn't a valid approach to managing an end user product regardless of the nebulous slippery slope freedoms argument you're attempting to make.
This is not an advocation to ban all adblockers, but you are advocating for basically a free for all, and we've seen how that works. It doesn't and this entire discussion is a waste of time.