Remember, it's not a fucking petting zoo. They are wild animals and they WILL KILL YOU if they randomly decide to.
People are so fucking stupid. That animal probably weighs around 2+ tons and if it stomps you, you are either dead or very, very injured.
The bison at Yellowstone are absolutely huge - some of the biggest bulls hit 6ft at their shoulders. Was there in 2017, and was utterly amazed at their size. Visited Custer State Park in South Dakota last Fall. In comparison they've got a big bison herd they manage, but they must have different genetics - much smaller than the Yellowstone brutes.
Both make for some good theatre though.
I have experience with bulls (cows). If you don't how what to do around animals like that they will kill you.
It is amazing that more people are not injured/killed every year in the national parks because they have no clue how to behave around wildlife.