I've been experimenting with Amazon's Polly service. It's their fancy text-to-sort-of-human-style-speech system. Think "Alexa" but with a variety of voices, genders, and accents.
The pronunciation of all the words is incredibly lifelike. If you heard it on the radio, it might sound like a half-familiar BBC presenter. It has a calm, even tone which suits the poem splendidly.
The rhythm is also spot on. That's mostly a function of the short lines and helpful punctuation the poem contains. Much like iambic pentameter, or a limerick, the syllables lend themselves to a specific and identifiable cadence.
But the emphasis is all wrong. The poem just... ends. There's no sense of finality in the tone. You'd expect a competent reader to recognise "tinned minds" as being worthy of stressing. Polly does have some capability to mark specific words for emphasis, but it's all very manual.
There's no synthetic emotion. Do you feel the rage, desperation, sadness, hopelessness of the poem? While Polly has some SSML (Speech Synthesis Markup Language) support - the range of emotions it can express are severely limited. And, again, must be applied manually.