What are the disadvantages of rendering?

Could you elaborate on the downsides of rendering? I'm curious to understand the challenges and limitations associated with this process. Rendering seems to be a critical aspect in various fields, but I'm sure there must be some drawbacks as well. For instance, does it consume a significant amount of computational resources? Or does it often lead to inaccuracies in the final output? Additionally, are there any specific challenges related to the time it takes to complete the rendering process? I'm interested in hearing your thoughts on these points and any other disadvantages you may be aware of.