Of course you do.
Home building is a skill that is specialized and therefore extremely manual. Consistent quality can only be guaranteed if machines are used and not human beings since human beings are more prone to mistakes. While the quality of two cars from the same production line can be assured to be similar to each other because of the level of automation used, two apartments that are next door to each other will rarely have the same quality levels.
A variety of factors affect home building: the quality of labour, quality of materials used, the time of completion, etc etc. For example, a house that has its tiles laid during the late afternoon will have a different number of faulty tiles as compared to a house that has its tiles laid first thing in the morning. Humans have different motivators that vary from time to time.
That is why, when it comes to construction activities etc, the only way of ensuring quality is by investing in stricter post production Quality Control activities.
While the builder must and should have in-house teams to inspect homes once they are complete, such teams will always have various constraints that would prevent them from doing a comprehensive job.
Therefore as a home buyer, it is always in your best interest to get a third party company with the necessary expertise to inspect your homes for you.