I've already equipped agents with access to credit cards that I generate at privacy.com and give budget caps to. It's just experimental amounts ($5-$50) and usually for paying for APIs or services to support the task. But it's all about risk management–I don't use models that train on my data, keep account and access contexts separate, and rely on service accounts for risky work instead of using my identity. We have to remind people that it's still the early days and things are changing rapidly. It reminds me of the early 90s and the flurry of innovation and the chaos that comes with change; this is all happening a lot faster.

Let's be more specific about how and why this could happen? What scenarios could lead to the total destruction of mankind?

Of course popular sites show up fine without validating. They're popular.

The key is the unpopular site - small businesses, for instance - that want to compete in search engines but will never have thousands of visitors a day.

Standards-compliant websites do not necessarily make for better SEO. But the practices and culture around them do.

Accessibility generally results in improved SEO simply by 1) increasing the placement of relevant text within a page and 2) making the site more accessible to search engines. Things like alt text go a long way.

As for download speed, you're absolutely right. It's a matter of data size. But standards-based design lends itself toward smaller pages simply by removing the need for repetitive code like

<font face="Arial,Helvetica,sans-serif" size="2">

It's not the standards that make it work well, but the benefits that come along with the journey towards those standards.

Nowadays, if a client isn't willing to let my company develop an accessible, standards-based solution, he isn't going to be my client. I just won't waste my time on them.