There is this hate/love affaire between DH and the TEI, which seems to me to be best expressed in the way DH scholars call the TEI the “de facto standard”. It’s not the standard you’d wish, but it is recommended, especially by the funding agencies who give money to DH projects. Also, it works, you can actually do things with the TEI that won’t disappear tomorrow. Of course, it is sooo heavy machinery compared to the time and funding you actually get from the funding agencies. But bummer. De facto, it is the standard.