The reason to start mining rather than just buying bitcoins should be because you have considered your interest to be interested in mining and also other factors that will make mining profitable to know if it is something you can do. If you consider factors like cheap affordable electricity, security etc and see that it's a check for all those factors, then you can start mining.
In early days of Bitcoin, it was possible to mine even on desktop computers but not anymore. The first thing you must consider before diving into mining is to calculate whether its profitable to do that? Electricity is the most important concern since the mining rigs eats too much electricity, the hardware for mining bitcoin is super expensive, many countries have legislation regarding Bitcoin mining. There are many questions one need to answer before starting Bitcoin mining.