Lots of sites warn you not to ride elephants as they are often treated poorly and don't have freedom (1,2).
But these sites also mention that it’s bad for the back of an elephant. With some elephants weighing 4,000kg (3), it’s hard to believe that a human weighing 2% of that weight can do any damage to it.
They aren't built for any heavy lifting (4). But I feel like it goes for any animal that they would be able to carry an additional 2% on their backs.
So how come elephants are so vulnerable to carrying stuff on their backs?