Nowadays, by development of biology sciences, there is no need for usage of animals either as food chain or for their products. I will give my reasons why I agree with this modernity effect.
It seems that by substituting other scientific ways of providing food, clothes or other animal products, the rate of unemployment would increase, lead to economical crises specially in poor economical countries. So many jobs which are directly and indirectly connected to animal industry would be eliminated, for example the rurals who are specialized in bringing up animals, business men who experienced to sell the animal products, and manufactories which produce nutrients and dieries may loss the most.
However, the advantages of not killing animals for human benefits are undeniable. Firstly and the most beneficial element that is resulted from this aim is to conserve animal rights. Although Thousands of years these species have been slaughtered for human requirements, there is now the time to end up cruelty to animals in the favour of science. This aim is ethically accepted by all men specially by vegans.
Secondary, by limiting animal hunting for human consumption, transmiting infectious diseases would decline, resulting a healthier society. Scientific data around the world for example, have been confirming that the diseases which are common between human and animal is at its lowest rate in vegeterians.
In conclusion, modern science which have been being substituted instead of animal business had some positive and negative effects. despite the detrimental effect that it would have on job opportunities, I personally believe the pros such as protecting animals and preventing sharing animal diseases, outweigh its cons.