Here are four reasons this would be a bad idea. Not to say his leadership is "working" in any conventional sense. The data is clear and widely known. Labour is tanking everywhere. He is widely unpopular with everyone outside his base. There is no clear policy on either of the two most important issues - Brexit and, related, immigration.
But here in brief are the five reasons to keep Corbyn for now - reasons that anyone (left or right) who wants to see the long-term existence of the Labour Party maintained should at least consider.
1. Good things are - very slowly - happening below Labour's surface. The membership appears to still be increasing. People are getting active in the party - albeit unevenly. Broad positions on investment, industrial strategy, fiscal and monetary policy are being sketched. New ideas are bleeding through. Excellent, young (admittedly mostly left wing) MPs are coming through - Angela Rayner, Kate Osamor, Rebecca Long Bailey, Cat Smith, Clive Lewis. This deep rejuvenation of the Party is vital in the long-run.
2. Corbyn could straddle the divide between liberal and 'left behind' voters in a progressive way and keep just enough of Labour's voter coalition intact during the Brexit process for Labour to survive. Corbyn is moderately eurosceptic, liberal and in economic terms an interventionist. Only that combination can appeal to both sides.
3. If another leader were in place - say, Chuka Umunna, Owen Smith or Yvette Cooper - all evidence suggests Labour would be offering another referendum on Europe and curbs to freedom of movements. In other words, the David Cameron 2015 position. This would be a disaster for many obvious reasons.
4. Yet another leadership contest would hit Labour's polling and demoralise activists. Corbyn has a mandate and his leadership has to be allowed to play itself out.
It's true that Labour has no clear position on either Brexit or immigration, but that's less because of Corbyn and more because of the many conflicting views in the party. Just as the Tory vote has been firmed up by Brexit, Labour's has been fractured. Changing the leader won't help.
It is worth recalling that Corbyn's policies are broadly very popular. But people don't believe he can implement them. There are two possible reasons for this and they are always at play when socialist parties propose radical changes in a neoliberal context:
1. People don't trust the political process - from the individual politicians to the institutions. They don't think politics does what it should and they don't see Corbyn as a break from that.
2. People don't believe that radical but desirable policies can be implemented in a time when market power predominates over the state.
Corbyn's issue is that either he personally is incapable of delivering in his promises or the system in which he's participating will not yield those reforms to him. Corbyn has a lot of baggage and his early days as leader were not exactly persuasive. But it will take time before someone on a surer footing, younger and better able to play politics, can sell Corbyn's popular policies in a way that makes people believe they can really be implemented.
Corbyn deserves another year. Then he - and all of us who want a radical Labour government - need to decide.