TikTok video sparks outrage online after it appears McDonald's drink cup sizes are exactly the same

A McDonald's worker claims he has proof that all the fast food chain's cups hold the same amount of drink. In the video the employee pours Coke from a small to medium then a large cup. https://www.dailymail.co.uk/news/article-8932401/TikTok-video-sparks-outrage-online-appears-McDonalds-drink-cup-sizes-exactly-same.html?ns_mchannel=rss&ns_campaign=1490&ito=1490