I do not like Orban at all and hate to agree with him, but I think he is right. I think there are two big reasons why Ukraine is unlikely to join the EU proper in the near to medium term:
The EU needs reform when it comes to deciding things when there is no consensus and this is now a very accepted position.The EU will only become more sluggish if we open the gates to another country with veto power.
Farmers. Ukraine is a big (and has potential to be even bigger) aggreculture powerhouse. Many laws (aggreculture subsidies etc) in the EU are not sustainable if Ukrain becomes part of the EU.
These problems are solvable, but take a lot of time I think. Also I don’t think it is in the EUs best interest to allow a war torn/rebuilding market into the single market, but here I could be wrong. Maybe there are reasons (like a way to exploit Ukraine after the war) that would invalidate my theory…
I would like to see the EU expand, but I think it will take a long time.