“Seems like the CBI agrees with that conclusion.”
One very good reason to treat it with caution, then:
https://capx.co/find-out-what-the-cbi-thinks-and-do-the-opposite/
“Do you really believe that we currently DON’T have any trade deals with the rest of the world.”
The UK does not have any trade deals with anybody. It is not allowed to have them nor is it allowed to negotiate them. The only ones we have are those negotiated by the EU that we have by proxy.
The customs union is a good idea. But unfortunately the model pursued by the EU does not suit the UK. It has to accommodate he requirements of 28 very disparate nations and quite simply it does not work properly for most of the member nations. It’s fine for facilitating trade within the EU (although some of its conditions are too onerous) but it is of very little use for doing so elsewhere. Bearing in mind that the EU is forecast to grow at a far less healthy rate than the rest of the world, we should broaden or horizons.