The EU only ever created laws in certain areas, mainly trade and standards related.
There are vast areas of legislation for which the UK Parliament always was wholly responsible and (frankly) more than enough to keep such inadequate actors fully occupied.
For example:
The sentence for burglary could have been increased to a minimum of 10 years. No EU involvement.
The state pension could have been doubled. No EU involvement.
We could have abolished and replaced the House of Lords. No EU involvement.
We could have reformed the education system in any way we chose. No EU involvement.
We could have introduced PR voting. No EU involvement.
We could have reformed local government in any way we chose. No EU involvement.
We could have made it legal to piss in the gutter. No EU involvement.
I could go on, adding to this list, almost to infinity. The EU was, and remains, a convenient excuse for UK politicians. The fact is most of them are lazy shits who can't be arsed to do anything much apart from talk twaddle and stuff themselves in their subsidised restaurants while they pass their time away before drawing the best pension available in the UK, bar none.
In fact, our politicians are so lazy and useless that despite the fact it was a matter of public concern, they made no attempt whatever to control EU immigration even though EU law allowed them to ask anyone not in a job or self-maintaining to leave after three months. Too much trouble, you see.