Of course there is. They can make it so annoying that the ads doesn't look that bad. They own the browser. They can make it so bad that even flash ads will look like a good alternative to all the work required.
All what work required? Proxying is an OS-level concern, not a browser-level concern. You set it up in your OS's control panel. The browser doesn't get to be a part of that workflow, so it can't make it annoying.
You are ignoring having a proxy in the first place.
Compare adblocking today: step 1, search for extension. Step 2, install extension. Step 3, there is no step 3.
Now convince your parents to install a proxy, then proceed to explain they can have it on each machine (don't forget phones and tablets!) or centrally on the network (now don't forget to explain about local network while at home versus 4g when they are away)... yada yada yada.
You're trying to make it sound more complicated by bringing up complex setups that novice users wouldn't need anyway.
The simple workflow:
Step 1. search for "ad-blocker" on your OS's app store/package manager;
Step 2. choose one [that happens to be a proxy daemon]; hit install.
Step 3. Enter your password when the app asks for admin permission to finish installing (i.e. to install the proxy daemon as a background service, and autoconfigure your OS proxy settings. But you don't need to be aware of that.)
