So you're giving up 5% to have a completely ready to go platform optimized for setting up a description page, create rewards, handle payments and everything you see on the KS front end. Then on the backend you have a bunch of tools to help contact your backers and post ongoing updates.
Back when I used KS, they took 10% not 5% and it was still a no brainer to use them instead of rolling my own platform.
Let's just say your campaign raises $20,000. That means KS will take $1,000. Even an MVP of KS would likely still take 3 months of legit full time development. Would you trade 3 months of your time for $1,000?
I wouldn't, and it's not just about the money too. I want to be in the business of doing freelance dev work and making video courses, not creating a crowd funding platform that I only used once or twice.
Plus, there's the credibility factor of KS. That holds a lot of ground on its own.
I don't think you can blame KS for your campaign flopping. That would be like opening up a store on your own, and then getting mad at the person who rented you the building because you're not selling anything. All they did was provide you the location to sell goods, it's on you to bring people in and convert sales.
Kickstarter is basically accepting money as a service with some unique twists. They never claim to be a marketing agency that will promote your campaign for you.
Sure, if your campaign gets popular you'll probably trend for that category on their listings page, but if you're depending on random people browsing KS to back your campaign then you're just setting yourself up for failure.
The long story short is, running a KS campaign is like running a sales campaign. You really need to plan a ton ahead of time, and ideally have an audience before you start the campaign, and if you don't have an audience, you need to find outlets to find people who are likely well aligned with what you're trying to raise funds for.
In other words, there's no shortcuts or guarantees when it comes to sales.