Specialized tools can be 10x as good for the job.

Often to save money or for convenience people will buy a multitool or generalized tool instead of a specialized tool. Depending on the use case there might be a specialized tool that is only useful for that one thing. One example is the fingertip bandage, it is shaped like a butterfly which makes the bandage less useful for most scrapes. But if you have an injury on your fingertip its hard to beat a fingertip bandage. They stay on very nicely and fit well. 

This concept extends to specialist engineers if your project can support it you want to hire specialists that focus precisely on subsets of your project. You want to hire a frontend engineer, a backend engineer and a data base expert. The issue is that you often cannot find specialists for every component, or there are many small areas that are too small to hire a single specialist for. This is when most companies turn to generalists. 

Specialists are expensive and only want to work on one sort of problem. Generalists are cheaper and will work on anything you want them to. As a result many companies slowly become staffed by generalists except for a few areas where the company itself is specialized. After a while, your company may consist almost entirely of generalists who are used to working on things that they do not know a lot about. The issue is that this effects your company culture and the ideas your company has on how software engineering works. 

A specialist will be working at 100% on day one of a project in their specialty. A generalist replacing a specialist you didn’t want to hire will take months to get to 80% of the productivity that specialist would have had on day one. If your company consists of mainly generalists, most companies do, you may not realize how much efficiency you are giving up by not having specialists.