I 100% agree with this assessment.
GoTriangle is competent enough at service planning and operations. They are just not set up to succeed at a major capital program. Bootstrapping one from scratch is really hard, their staffing level was thin to begin with (and indeed, even thinner after DOLRT’s demise) and the board members are all taking this on as a tertiary role or worse, so they don’t have the proper time to stay on top of things and oversee it properly.
I actually emailed the board members representing Cary and Wake County last week to suggest exactly what you have said- hand this over to NCDOT.
However, GoTriangle cannot simply vanish. They are the organization that our transit tax funnels into and I imagine that if GoTriangle disappeared, the transit tax might disappear as well.
Their role in the commuter rail project should shift from primary sponsor, to stakeholder (=source of funding, operator, service planner) with NCDOT taking on the role of project management. This would be basically handing off the commuter rail project to NCDOT Rail in the same way that they handed off BRT to Raleigh.