Direct to garment has a specific niche. Direct to garment color can be as good as screen print. Machines that print on dark shirts are expensive and a pain to maintain because the white base that allows you to print on dark garments have to be purged and cleaned from the machines nightly.
If you are talking about high volume of shirts, 144 or more, you will want to do them screen printed.
Direct to garment is a slow process and your production time will be ate up waiting on one shirt at a time.
A multi-head automatic screen press can produce a dozen shirts in the time it takes a direct to garment to produce a few.
Direct to garment like I said fills a niche, one that I don't have the time for because the market isn't very profitable.