We do print at the studio. Not very much. Our Epson inkjet produces good prints, and the inks are claimed to be very stable, but there are easily available firms with huge printers who calibrate them daily and use them steadily througout the day. For much work it is better to have them do it.
There are several reasons we or you might prefer a print to be made in house, ranging from not wanting anyone else to see it - until invited - to being an experimental work and wanting a rapid iteration.
And at least one reason for walking round the corner to a very good specialty photo-printer there and discussing what paper to use for a particular image, then printing it with individual attention and immediate approval. So we can do that.
A reason we are less keen on is to do with pricing and profits. There is a temptation, or a business model, in photography to do a shoot – take the photographs – essentially free or rather cheaply, and then sell individual prints at a large markup. The risk is that the customer, client or subject feels cheated receiving a print that is of a size advertised as available for £5 by post from an online printer for a charge of £300 and/or disappointed that they can't print several of the images and print them large - they end up with less than they'd cheerfully buy. The alternative model of charging rather more for a shoot, and then providing the image files and a little advice on where to send them for printing does leave the client with some of the work and risk.. We'll do it either way.