In the sense that someone sending you a surprise crypto miner with their webpage or bundling a botnet trojan into a program they give you is just them putting it on their own space, sure. If they send it to me though, my security software will promptly filter it out or otherwise not allow it to run. My firewall will block connections to their known-dodgey payload hosts from all computers on my network. My computer is not for running someone's miner, and that's not the intended purpose of allowing scripting. Likewise, my screen is not for displaying ads; it's an abuse of scriptable documents that gets filtered out. Opening a web page doesn't create some obligation to run malware.

fwiw making an offline analogy, I also live in a city where outdoor advertising signs are generally banned (with some exceptions like saying the land is for sale, or small ground-level signs with height/width restrictions at an entrance indicating which businesses are on a lot), so even on their own land/their own space, businesses putting up things like billboards would be spam and disallowed.

The FBI literally suggested people block ads to avoid being defrauded. My understanding of the web was that it was first and foremost a non-commercial space, and spammers have always been impinging on that. Blocking their nonsense has always been the correct course of action.

In the case of children, I actually strongly believe it is immoral to allow then to be inundated with ads. It runs completely counter to teaching them virtues like temperance. It is not just "convenient" but an actual moral imperative to keep them away from those who would push consumerism onto them. This has only become more obvious as climate change worsens as the top problem they will inherit, or as we see 70% of adults in the US now destroying their bodies with disordered eating while still ubiquitous ads encourage them to continue. Ads are a blight. Allowing them to reach the next generation is somewhere between neglect and abuse.

So no, your idea of these things is not "our shared understanding".

Even when the Ins and Del are there, they're at the far right top of the keyboard, which requires moving the hand to reach them every time.

It used to be less of a hassle when those shortcuts first appeared (with IBM CUA), as Ins/Del were just slightly above the arrow keys that you'd use to select the text prior to copying/cutting it anyways.