There is a lot of truth in this statement, but it is possible to adapt to change and preserve jobs by changing them. Germany has a shipbuilding industry still be, by making cruise ships, while the UK has failed to adapt in general and lost nearly all of its civilian shipbuilding.
Part of this adaption process should be facilitated in some part by differing Governments such as EU and UK. It hasn't happened enough in left behind areas hence the decline in economic activity. Government can give subsidies, grants, provide some trade protection, change tax levels to incentivise etc. One example - The EU spends 40% of its budget on subsidising farming to protect farmers and rural life within the EU. It also ensures farmers are protected with tariffs and quotas on some food stuffs goods entering the EU from outside. The UK is a big contributor to this subsidy, not many on Teesside benefit though. Another example is investment in public infrastructure, CrossRail (in SE England) has being in construction for 12 years and will cost about £19 billion, while Middlesbrough station is from another age and part of it unusable for lack of investment it serves around 200,000 people! Not EU's direct fault but certainly a victim of lack of interest from the UK and EU Governments until recently. That sort of major investment lays the foundation for a successful economy.