For me, the top of these is accessibility. Obviously people can write code they like for fun and free, but governments are increasingly, and in my opinion right

For me, the top of these is accessibility. Obviously people can write code they like for fun and free, but governments are increasingly, and in my opinion rightly, saying that if you want to sell a product it must be accessible if that is reasonable. People like Apple, Microsoft and browsers put lots of effort into this if you use their existing frameworks right.