That is my whole point, it was blinding obvious from the start that there never could be a 'good deal' because; a) that would have laid the EU open to a number of other requests to leave the club from others; b) A point well made by the EU and others, was that you can't have the same situation outside the club as being a member.
Hence the UK Government should, if it wanted to honour the results of the referendum, have given notice via A50 that it was leaving and spent the next 2 years making contingency plans for a 'No deal' scenario in the UK. There was IMO never any prospect of a 'good deal,' the withdrawal agreement favours only the EU (naturally), because they always insisted they couldn't discuss trade until we left the EU, so the priority for us was to leave, then see what terms for trade we could get, balancing the needs of our exporters, with those who import from the EU, as we will finish up having to do, if we leave (deal or no deal).