Evidence comes in many forms. There doesn't appear to be evidence in the form of a recovered weapon or technical recording/logging of an attack as it happened, at least nothing that has been disclosed.
However, the injuries are real and ongoing. It took a long time for consensus agreement that these events were malicious targeting by hostile govts against our diplomats, using remote energy weapons. Even just with the evidence made public, it's the most plausible explanation.
It's not the most plausible explanation, but it is the most convenient one. It shifts the blame and reinforces the narrative. They don't even have a coherent idea regarding how such a weapon would work in practice, it's pure speculation.
https://www.washingtonexaminer.com/opinion/us-intelligence-g...
Consider the last paraphraph of the article:
> "Most importantly, if and when more evidence is gathered, Putin, Nikolai Patrushev, and their officers must be held to account."
This is not "news", it is war propaganda. Besides, it's immensely hypocritical. When was American government and intelligence officials ever held to account for orchestrating and instigating violent aggression abroad?