Why are you assuming all workers rights will automatically disappear after Brexit?
Our maternity/paternity rules for workers are far better than EU directives.
The trouble with Brexit, people are obsessed on the doom and gloom.
Many Tory MPs currently in cabinet positions, those in the "ERP" and other Brexiteer MPs (who have had far more media exposure than their intellect or positions have warranted) have called for the UK to become a low tax, low 'red tape' economy. Some of these MPs have outside interests who will greatly benefit with reduced 'red tape', lower taxes and certain nationalised sectors being opened up.
'Red Tape' is actually employee protections, consumer rights, product safety, EU wide harmonised standards. Some of these will entirely likely be pushed as being flexible in the case of a no deal, because countries wanting to deal with the UK on WTO terms will demand it. Whether it's lower food standards, lower electrical standards, working time directive changes etc etc.
I do not trust any of the current Govenment to leave these things untouched, based purely on their appalling record over the last few years, and what many of them have said during Brexit. How anyone else still has faith is beyond me.
We're "obssesed by the doom and gloom" because that's all we see. We don't see any positives. We see a government and significant portion of the population trying to continue with something that ALL the experts (with no vested interests), Govenment data and people who are properly read say is utterly crazy. A vote which never should have happened, that was based on lies (from both sides), fraudulent and with most people completely uniformed.