Actually there have been articles about it:
https://www.mirror.co.uk/news/uk-news/former-mcdonalds-worker-lets-slip-20716313
Short version: they’re built to fail and require the company ($$) to do service calls.
Yet the article you linked said the real reason is that they take three hours to clean each night.
I don't know about the machines today but the ones we used back in the 1980s worked just fine.