An opinion holds that animals these days are not essential to provide as a source of food or other products, like medicines or clothing. While this may be true to a certain extent, I would argue that animals still play an indispensable role in this situation.
Regarding food sources, although eating alternatives like vegetables or fruits can protect animals, which is very ethical behaviors, it usually does not ensure sufficient energy for an ordinary person, not to mention patients, or pregnant women, who need extra and nutritious food to rehabilitate or provide nutrition to their infancy. Nowadays, it started existing cultivated meats made by scientists, which boast similar tissues and flavors like flesh from animals, but this form of foods is still in progress and not popular.
In terms of medicines, since killing animals is very immoral, using them in experiments is very crucial because many species, such as monkeys, or mouses, have numerous same features, like organs, or even illnesses as humans, facilitating medicine productions and shorten the time of experiments, which is very important in emergency cases like pandemics, reducing a significant number of deaths.
Considering clothing, clothes that do not need animals usually keep warm less effectively than those using furs or wools, which is very important in winter or places having low temperature, like those in high altitudes or near poles.
In conclusion, although taking advantage of animals is unethical, I believe they are very needed to produce essentials for humans because of the incomparable effectiveness of nutrition, medical experiments or keeping warm