Building on your analogy: Currently we spend a lot of time and effort making sure our walls appear nice and inviting, with lots of convenient entry points where advertisements can be placed. In the future we will build ugly walls with a few well guarded entrances.

What I mean is, look at how much time and effort we spend on making software services beautiful and branded, and so little time spent on security. In the future we'll probably have fewer webpages and more hardened text-based APIs that end users interact with via their AI agents.