I actually feel sorry for May. Yes she's weak, indecisive and not a natural leader but she has no options. Her party remain divided. The in the customs union vs out of it has become the new battle lines for anti and pro EU Tories. Moreover, May's been tasked with a wishy washy mandate to 'leave the EU' which was built largely on lies. For example that the UK will prosper outside the customs union, when ALL of the evidence shows the UK will suffer financially. May is not in a position to negotiate on an even footing with the massive EU block, why did anyone think (and continue to think) that we could? Yet the deluded (or lying) politicians who said it'd be easy to dictate terms to the EU remain in key positions in government and this brexit process, undermining pragmatic realism. Why have they not been pulled up on their inaccuracies? However, is May as bad as she's made out, or actually doing a fair job picking a way through the impossibilities of 'Brexit'?
You could argue that a more staunch PM, a more extreme one way or the other PM - out the customs union on in it - would actually bring things to a head quicker. We'd get another general election quicker and the UK could address. Maybe May's greatest criticism is that she's just about keeping a lid on it all, so perpetuating an impossible position which will, at one point or another, come to head.
France wants our city jobs. It's become clear that Frankfurt is a dull boring place to be. Paris is London's natural successor. Just as London replaced Zuric. London will still retain its old institutions like Zuric does, but there would be a shift towards Paris over time imo. France, already overtaking the UK as the 5th largest global economy, displacing us, are exited by growing their financial services for Europe. Therefore we will not get an EU free trade deal where we can make our own trade rules etc and retain free trade of services with the EU. A number of EU nations would not be happy with it (though arguably maybe a few would). Such a deal would totally undermine the EU. It would make being out of the customs unions, better than being in. The UK would have everything good from it, and none of the downsides.
Despite these realities coming home to roost, the mad-for-it Brexiteers plough on, unable to let go of their ingrained positions and egos. The UK still has no post-brexit vision, and is suffering financially for it. We need a new vote as soon as possible.