Out of your posts, I like what appears to be a genuine concern for the younger and future generations
With Brexit, they will hopefully get more democracy and greater long term prosperity. On the latter point, the freedom* of oppurtunity to sync the British economy with larger and rapidly growing economies, will hopefully generate the wealth to allow a generous 'welfare state' ** it will be much harder to do that if tied into a protectionist organisation, with a protectionists mindset that is likely already on a course to have a shrinking share of the world's economy.
History has already started to make the 'Occident' insignificant. I'd rather the younger/ future generations that will see out the best part of the 21st Centuary, will do so in an economy that is tied into the rapid growth of the 'new world'
* in this post i'm referring to a specific nuance of freedom, namely having greater ability to trade and 'freed' from the constraints of multiple internal vested interests that are associated with protectionism, and having a 30th (ish) share of say in a consortium
** I'm customising the term a little, but I'm refering to return to free education, continuation of the NHS, free elderly care. We may be able to even stretch to a higher spend on international development if enough people are up for it