and you'd lose most of your audience. there's a reason that youtube's creators are still on youtube. Thinking about the people who watch a youtube channel as that channel's viewers is mostly a mistake. Some portion of a channel's subscribers would follow to a different site, but most of the audience of a YouTube channel is YouTube's audience. YouTube is sending the audience to videos via the popular feed, suggested video links, up next, the subscriptions page, and all their other discovery tools. Only the most hard-core fans will move to your branded content site.
And even when the audience moves, then you're doing ad sales yourself instead of taking advantage of all the companies doing big bulk ad buys on youtube, and paying for hosting yourself. Bandwidth isn't free, and youtube is very efficient at hosting and delivery. Other video sites tend to suck. Best case scenario, your pre-roll or banner ads pay for your hosting and ad sales work. The only profit you should expect to retain on your branded site is the in-video placements you're already doing on YouTube, and your Patreon revenue - the things YouTube demonetization can't affect anyways.
The pathway for a content creator to exit youtube is to sign a TV deal. Dedicated channel websites don't work.