I would disagree since I believe web agents and computer using agents that act like human on the web do need a way to authenticate and UI has a big component to that. A2A works with implicit OAuth Flow but for web agents and computer using agents having a flow of OAuth 2.1 + OIDC is rational. Check this repo out once https://github.com/auth-agent/auth-agent. I do want to read the article fully and I will get back to you. Thanks for the article!