If the Scottish people want to live in a more socio-economically equal/successful/etc. society than today's UK then they have two ways of realising that. One is to emigrate out of the UK, the other is independence. Scotland in the Union will never be significantly different from the rest, the UK has put in a mediocre performance for decades (sometimes below that too - check out historical comparisons). The UK will arguably remain mediocre or worse lagging behind the most successful societies for the foreseeable future (unless you place extraordinary hope/faith in Brexit and its effects), including without an independent Scotland - it will be neither better together or worse apart. Scotland can hope that independence will provide the option of change, being different from the UK, and life actually improving faster than it has/will in the UK. There is evidence that many/most Scots have faith in themselves and believe it is a worth while step to take.