This might seem either cynical or naive, depending on your opinion.
Russia will have to pay for the reconstruction, similar to how Germany had to pay for WW2. It will benefit both Ukraine and EU to have EU contractors do the work inside EU. Even if Russia takes 50 years to pay off the debt, the money is toll free and flowing from day one inside EU if Ukraine gets to join.
Yes, minefields will take a long time, unless new technology is deployed. There are still no-go zones from WW2. Hasn’t stopped the world from turning.
The Ukrainian economy is predicted to be strong after the war. It’s not just a poor shithole bomb field. Before and even during the war they were and are a key source of agricultural products to the entire world.
The reason Ukraine has been a poor country is not due to lack of production or unwillingness to produce. It’s been due to corruption. Corruption originating in people linked to Russia. The current president pledged to clean the country from that and so he was attacked by the people benefitting from their poverty. Ukraine is strong and will be stronger within EU when it has rid itself of corruption.