Right but like I said before, hiring a coder would come with a lot of legal requirements that a lot of people might not even know about. Like for example, he hires a coder whose working on the project, has some sort of accident in their own house, (say their chair snaps and they fall and hit their head), because they were on the clock working on this game, cyan would then be liable for (I think it's called) workers comp and health insurance etc.
I'm not making this up, employing someone especially for a long-term project like this makes them liable for a lot of things like that. Once you hire someone that makes you an employer, meaning you have to declare, pay insurance, pension etc. Like if they ever check his income through patreon, see he was paying someone out of it but not declaring it then they can get a fine. Source: I did a business startup class for almost 2 years.
Yes, it could speed things up MASSIVELY, but unless you're planning on setting up a full fledged indie studio there's WAY too many restrictions and red tape in the way of things. Plus there's the fact that cyan likely has a family and life outside of the project and doesn't need the extra hassle going into it. Plus it wouldn't necessarily speed things up if you have to bring in too many people, like take dark cookie from summertime saga, the guy (allegedly) has about 5 people on the team and yet updates are coming every couple years at this point