Read this,
6 Key Differences — "Shared Hosting vs. VPS Hosting" (2019 Guide)
Long story short, with a VPS (or dedicated server) you are running the show, with a site this big you probably want to setup automated tasks to pull DB backups, potentially mirror two servers every day for redundancy and load balancing. Have processes that run in the background that sizes and manages image uploads, automate admin alerts if the site goes down... just throwing out ideas. Yes you can do some of this stuff in a round about way on shared hosting, but if you have a platform that people are paying for (TFP sponsors) you really need the tools to back it up.