LAMP is one of my favourite things. GNU/Linux under Apache web server with MySQL database and PHP is a neat, flexible and powerful tool. PHP is not my favourite programming language because it is fast in development but slow in execution but it is popular. That might explain why Apache is a very popular web server on that other OS.
According to W3Techs, of the web servers of which they know the OS, 66% run Apache, 18% run M$’s IIS, and 10% run Nginx but 36% run that other OS.
What puzzles me is why anyone would use that other OS to run a web server. There’s no need at all technically. It must have to do with the local culture. Perhaps the licensing for one extra server on the web is already covered by a site agreement. Perhaps the management system in use is M$-only. Perhaps the bosses only know M$. Perhaps people don’t consider web-servery mission-critical. Perhaps…
It’s certainly easier to run a LAMP server. No purchasing required except for hardware. No need to allow audits by M$ and “partners”. No need for so many re-re-reboots. No need to accept malware as a normal part of IT. No need to re-install during the life of the server. Less downtime. Better throughput because the OS is not working for M$. Easier to install. No EULA to “accept”. No authentication code to record for posterity. No licensing fee. Simpler accounting.
On the desktop, the situation is the same. All kinds of people are running FLOSS apps but they have that other OS underneath for unknown reasons. Many people cannot even tell you what OS they run on their PCs. They just run what came with the PC. On many occasions I have had people use GNU/Linux without them knowing. The applications work as expected. The windows work as expected. The mouse and keyboard work as expected. There’s just no need for that other OS for most people with most uses of IT/PCs.
All kinds of people and organizations have switched from that other OS to GNU/Linux with few real problems and many advantages. They just got on with their lives with better IT.
I recommend Debian GNU/Linux. It works for you.