There are some "ungrading" practices that are useful, but the grade earned serves an important credentialing step, and clearly showing students the skills they need to master is the whole dang point.
1) I would argue that most questions we are asking students in technical courses shouldn't have right and wrong answers...it communicates the wrong thing and reinforces the assumption that technical work is 'getting the right answer' for students. College level technical teaching should work beyond that norm towards using 'right answers' for decision making
2) While there are similarities and they are often used interchangably, standards based, mastery based, and specifications grading are not exactly the same thing.
2) True! You really have to be careful even within terminologies. There are lots of different implementations of mastery-based grading, for example, and they're subtly different.
And a final note: we're of dangerously similar (but not quite the same) perspectives! https://www.youtube.com/watch?v=ANNX_XiuA78