There are good reasons why regional air carriers are still needed. The need for them remains even despite the fact that many people fail to see their importance nowadays. Regional airlines have not succumbed to globalizations and increase in population yet. Actually, they are very unlikely to perish any time soon.
Remote and scarcely populated habitats
There are still many remote places around the world. Most of them have low population levels and inhabitants are spread over large area. Road and railway networks are often insufficient and more importantly – they do not connect these areas to the rest of the world. Even if they do, the time required for reaching the nearest larger town or a city is very unreasonable. However, locals often need to travel, be it for business, medical or recreational purposes. At this point, regional airlines step in. They fly smaller airplanes. Much fewer passengers are needed to cover the cost of these lines. So, regional airlines can stay in business and they provide much needed service to locals.
They often transport goods too. People living on remote islands and other areas are usually not self-sufficient. There is often lack of food, medication and other stuff. Regional air carriers transport most of these goods. They can also move goods produced by local. These goods are usually used and sold at places far away from where they were produced.
As you can see, many people still depend on services provided by regional airlines. These airlines are the only convenient option for them. Some people might argue that mainline airlines fly to some such places too. But, this is not true. Sure, airplanes often fly there under the strong brand of these big airlines. However, many people do not know that these lines are actually flown by smaller separate companies.
Filling-in the gaps
Another important reason why regional air carriers are still needed is that they often fill-in the gaps for mainline airlines. The air traffic is often increased on certain days or occasions. However, the increase in demand is often not high enough to justify addition of mainline airplane with 100 seats or more. Smaller regional airlines cooperate with mainline airlines on such occasions. They provide smaller planes as running costs of these planes can be covered easily.
To conclude, regional air carriers are still needed nowadays. Even the two most obvious reasons are enough to justify their existence. After all, people living at many remote places would have no convenient option to travel in case regional airlines did not exist. They would also suffer from lack of food, medication and other stuff more often than they do now.