New Judge,
UK should voluntary (certainly not forced) agree to treat EU citizens better. Many countries welcome Europeans and consider them to be well cultured, as well as economically adequate & sophisticated. The majority of people emigrated from Europe to the British Isles, Australia, New Zealand, Canada, USA, etc over the centuries. Europeans are the ancestors of the majority of current Britons (including our monarch).
https://www.ucl.ac.uk/news/news-articles/1114/051114-economic-impact-EU-immigration/ stated, "European immigrants who arrived in the UK since 2000 have contributed more than £20bn to UK public finances between 2001 and 2011. Moreover, they have endowed the country with productive human capital that would have cost the UK £6.8bn in spending on education. Over the period from 2001 to 2011, European immigrants from the EU-15 countries contributed 64% more in taxes than they received in benefits. The net fiscal contributions of recent European immigrants from the rest of the EU totalled £15bn. Immigrants who arrived since 2000 were 43% less likely than natives to receive state benefits or tax credits".