No, it's not. Why should disabled users be forced to indirectly interact with a webpage via a non-deterministic agent, rather than directly interact with one that's specifically designed to accommodate them?
Because a world where that happens consistently doesn't exist, it hasn't existed for the last 20 years we've been using ARIA tags, and won't ever exist.
1. A robust set of web primitives that are accessible by default, and
2. A government that will actually enforce laws (which already exist!) requiring websites to be accessible
As mentioned ARIA has had 20 years before by Hakcer News post. It will continue to fail with out without me.
As a developer, however, get your shit fixed! And that fixing doesn't involve any MCP. Don't expect visitors to run AI...