WordPress is the world's most popular content management system powering 34% of all websites on the internet. On top of that: WordPress has a 60.8% market share in the CMS market. WordPress powers 14.7% of the world's top websites so security and scalability is never an issue if managed properly.
I have worked for Fortune top 500 companies and helped more than 100's of clients in creating startups using wordpress and most of them are still running successfully. You can schedule a call for more detail or refer https://www.fiverr.com/mvpexpert/create-an-online-marketplace.