They are "no longer strong enough" to the extent that GitHub, backed by Microsoft, has had to indemnify their GitHub Copilot customers against copyright claims,

They are "no longer strong enough" to the extent that GitHub, backed by Microsoft, has had to indemnify their GitHub Copilot customers against copyright claims, and to provide a feature to explicitly prevent open source code from being regurgitated into your codebase. That's not "no longer strong enough". That's a very strong system applying leverage to a powerful actor.