It was made pretty clear that having the freedom to strike our own trade deals when we want, with who we want, prioritising our interests rather than diluting them for 27 others was a potential benefit of leaving the EU. Of course, other opnions are available. I doubt you have the same views as all other remainers on this thread (eg rabid Federalists or far left loons).
In what way has the European way of doing trade deals been bad for the UK at all? You make it sound like we're suffering under the status quo - we're not! We had a lot of 'freedom' to strike our own deals with who we wanted, when we wanted back when we could sail a few gunboats into port. We aren't going to dictate terms to anybody in 2019.