► If you use innerHTML the content is replaced everytime.

► We cannot use like 'appending to innerHTML'.

► Even if we use += like "innerHTML = innerHTML + 'html'" then also the old content is replaced by html.

► If we use innerHTML then the entire innerHTML content is re-parsed and build into elements. Therefore it's much slower.

► The innerHTML doesn't provide validation and therefore we can potentially insert invalid and broken HTML in the document and break it.