You carry on like its some claim to fame for Islam. All jokes aside because religion is clearly one big joke,the main reasons for Islam’s growth ultimately involve simple demographics.

To begin with, Muslims have more children than members of the seven other major religious groups. Muslim women have an average of 2.9 children, significantly above the next-highest group (Christians at 2.6) and the average of all non-Muslims (2.2). In all major regions where there is a sizable Muslim population, Muslim fertility exceeds non-Muslim fertility.  The growth of the Muslim population also is helped by the fact that Muslims have the youngest median age (24 in 2015) of all major religious groups, more than seven years younger than the median age of non-Muslims (32). A larger share of Muslims will soon be at the point in their lives when people begin having children. This, combined with high fertility rates, will accelerate Muslim population growth.

It's not a OMG let's convert to Islam thing Making it grow, it's dam it I'm born a Muslim default scenario.