What I keep hearing is that the major impact hasn't been so much from Brexit itself, but it's created an atmosphere of such complete hostility towards the left (since they were mostly the ones trying to stop it) that the major left-wing parties and even left-wing values in general have been pretty much permanently discredited for the majority of the populace...
...and that Boris Johnson seems to be trying to fuck this gift up as hard as possible by deciding that what his party really needs to cement perpetual electoral dominance over the country is to become vastly more left-wing, even beyond the steps that COVID forced him to date.
Is that an accurate description of things?
No, in a word. The traditional British left, the real left rather than the new-right Blairites, traditionally hated the EC as it was. They pushed for an 'out' vote in the 1975 referendum on continued EC membership. Thatcher, post 1979. The working class left saw the EC/EU for what it was, a new-right project designed to create a conventionally right wing economic structure, masked by socially progressive attitudes to identity politics, the environment and so on. The working classes didn't like it for that reason, and for the fact that it later brought mass immigration and downward pressure on wages as a result. Eu membership also, funnily enough, requires a state to take a wrecking ball to the various pillars of traditional socialism such as national ownership of major assets and centralised economic planning. You have to be centre-right, or you ain't getting in, in a nutshell.
The old fashioned right never liked it, fearing that it would erode sovereignty. They also saw latching on to Europe as something damaging to the Commonwealth, which they love to bang on about as it's the last vestige of the Empire.
The new right, including the modern Labour party, love the damn thing. Why? Because they want everything it provides and dislike the traditional working classes.
There's also the silent majority: those on the right who don't toe the modern party line. Nigel Farage is their Godhead. They hold some of the ideals of the old fashioned right, and also cling to somewhat hubristic beliefs about going it alone and 'cutting red tape'. It would all be fine and dandy if there was no red tape. A likely story.
The modern establishment left: Labour, the SNP, the Greens, the putrid remains of the Liberal Democrats and so on are not really left wing in any meaningful sense. They are just soft Tories who are seen as nicer because they want to turn the entire country into a multi-faith, ethnically diverse, disabled-access, all genders safe space for the chattering classes whilst the politically exiled landfill whites sit unemployed in their crumbling wrecks of social houses or prostrate themselves before Jeff Bezos.
Brexit is the first decisive thing the disenfranchised class has done for decades. As noted above, wages have risen in some sectors. Nothing else has happened.
The establishment left has, to a degree, been discredited. It has become apparent that they offer nothing more than the Tories, and more to the point they offer nothing different to the Tories. Red, Blue, whatever, they're all the damn same. That's what has led to them becoming discredited. There just isn't a reason to support them any more; the demographic that economic right/social left appeals to is small, and is likely to vanish in the event of a severe economic shock.
Opportunities? I think so. The economic left has been battered, but is ripe for resurgence.