I wouldn’t say that it’s required but it is considered a good practice. The reason is that by segmenting the market, you are able to develop products that are better targeted which means higher conversion and higher turnover.
You can segment a market either by income or by using different demographics (culture, sex, age etc.). By doing that, you can better understand what your customers need and you can develop tailored products and create marketing campaigns that are more effective.
The ultimate goal is to grab a bigger market share by delivered products that suit different needs based on the demographics you have used to segment the market.
In addition, by segmenting a market you can develop more cost effective internal structures (logistics for example). In other words, market segmentation can be done based on location.