You know the average attention span in 1920 was 5 seconds. This is a theatre statistic. 'Vines' originally capitalized on this very fact, and tiktok only extended the logic. A person had to add emphasis or switch tone at the end of each 5 secs to reinvigorate the attendant before losing their attention or hypnotizing them. This ( the human brain) hasn't changed much in 100 years.