I believe joining the EU would boost the economy, increase global influence, improve collaboration and provide stability & freedom. I believe that Brexit hasn't brought any tangible benefit and there is no future prospect of any, that the UK has changed its mind and that this should be recognised.
Even during early phases of Brexis the EU was open to the UK rejoining - in an official manner.
I don’t see why that would have changed. If the UK wants to rejoin, it can apply, and the join process will start. It’s simple, really.