“[Coelux][3] makes a high-end artificial skylight which certainly looks awesome, but it costs upwards of $30k and also takes a lot of headroom in the ceiling.”
Dark winters are partly a lighting problem, and the fix is just a lot more lumens. The DIY version is a pile of cheap LED bulbs. The commercial version is a $30,000 fake skylight. The post’s whole pitch is that nobody sells the middle, and that is a better business plan than most startups have.