Abbas may be corrupt, but most leaders are. It’s not acceptable, but it’s the reality. On a side note, Nethanyu’s trial for corruption restarted today.
Hamas and PLA (Fatah party) did draw up an agreement to have elections across all the occupied territories for a coalition organisation. They got the US to agree to it, but Israel refused to allow it because their geopolitical objectives have always been to divide Palestinians. So there are back channels between Hamas and PLA, it’s one of the sources of the allegations of corruption. But then how can Fatah hope to regain representation of Gaza without communicating with Gaza authorities which are administrative arms of Hamas? It’s similar to how many accuse Qatar of corruption and being too cosy with Hamas without realising they were literally asked to set up an office that mediates between the US and Islamic terrorists (among others) by the CIA. They’re not best friends with Hamas that’s not how or why they took on the mediator role, it was a deliberate move by the US to help keep the entire region stable. (I realise you haven’t said you have this view, saying that others have expressed it)
[ I am saying coalition organisation and representation as neither PLA or Hamas have self-rule or power of governance. They have less power than Britain allowed the colonised in its colonies]