Microsoft IIS

IIS as a web application server is perfectly suited for .net, .net core, asp.net applications. Our core ESB runs on IIS and has hundreds of gigabytes of data moved through it every day spread across millions of transactions. We have other mission critical applications that deliver our results to patients and doctors relying on IIS web application servers. If you stay in the Microsoft development stack, IIS is a top tier, efficient, and reliable web server.

I consider IIS a good solution when you have to publish internal web applications, but I feel to suggest to use other system, for security reason,if you need to go outside your organization.

Microsoft IIS is great for Intranet, where all users are on Windows and they require access to web sites that can be controlled by Active Directory groups.

I would recommend it if you use a Windows environment and have to utilize a medium processing load. If you have high availability loads, I'd recommend a more simplified webserver like Nginix or Apache. They provide a better threading model for resources.

Microsoft IIS is well suited for simple website hosting and for more complex web application setups as well. Granular security features allow you to make your web site or app to be protected as much as possible. Plus by default the best integration with other Microsoft services like Active Directory, WSUS, SCCM, etc. However, if you need just a basic website that is not based on MS components, open source solutions like Apache or Nginx could be better and cheaper (based on Linux).

Well suited when utilizing Windows servers that require multiple sites to be deployed and you don't want to employ multiple services to run different applications

Many commercial off-the-shelf (COTS) vendors only support Microsoft IIS, in these cases I would not recommend trying to make it work with other platforms such as Apache. If you are in a primarily Microsoft Windows Server environment, I would recommend using Microsoft IIS as opposed to trying to make Apache or other web platforms run on Windows. If you have an abundance of Linux knowledge in-house and the application supports Apache, I recommend using Apache on Linux as a more optimal use of resources.

Microsoft IIS is well suited in several different situations. If the native support and better compatibility with ASP.NET framework sites is needed, it's better to use a Microsoft IIS web server.
Running Microsoft Systems management tools like WSUS and SCCM, you are required to use a IIS web server. Also, IIS might be slightly easier for anyone not experienced with a web server. Especially with the relative ease of install on any modern Microsoft Windows OS.

However, for sites that don't require Microsoft components. It's going to be more beneficial to run a Linux web server. This is because you will get better performance, better security, and the large community support behind open-source projects like Apache and NGINX.