Even just the security concerns and having any confidence in the implementation is likely a specialized skill, so you'll need to convince someone to work for free or be able to pay them. Now do that for other major lines of work like UI/UX, Ops, and QA.
Take a look at all of the features from GitHub or any code platform that you'd need to get people to sign up these days (because they are used to GitHub/others) and it's a very tall list. Think something like https://www.enterpriseready.io/ but definitely larger (maybe 2x, 3x as large).
Oh and if someone writes a long rant about it and it gets to the top here, it likely becomes dead in the water, and you can't get the time back, making it a risky proposition. At least with VC money, you got paid a salary.
The aim doesn't have to be "Be the next GitHub", but something else, and that's just as valid and "successful" as anything else, as long as they survive as communities.