FPTP firmly entrenched the two party system and it would take a herculean reform effort to uproot it.
And yet, Britain's next election will likely be a contest between Reform and the Greens. The center has collapsed and both centrist parties revealed themselves to be incapable of meeting the challenges of the moment.
Yes, you're right that FPTP produces a two party system. But what people who point this out miss is that those two parties can be switched out. And the nature of power structures means that it's usually easier to just let one of the entrenched parties completely die than to try and reform it from within. Remember, the Republican Party started as a third party before becoming one of the two main parties. The abolitionists ultimately found that starting a new party was more practical than trying to work within the existing two party structure.
It was possible to reform the Republican party from within, but that likely isn't possible with the Democrats. The MAGA wing was able to take over the GOP, but ultimately their message is no different than the same crap Republicans have been pushing for generations. They're not fundamentally challenging the core beliefs of the party. Trump still takes his court nomination orders from the Federalist Society. He still gets his social policies from the Heritage foundation. Racism is still the primary party value. Very little has actually changed, aside from more nakedly fascist methods.
In contrast, reforming the Dems would require fundamentally uprooting their core values and power structure. And historically that just isn't very practical. It's easier to just create an entirely new party than to try to completely transform one. At that point, you're basically creating a whole new party anyway, just within the shell of the old one. Even if you succeed in taking over the Democratic party, all their old financial backers and supporters of centrist policies will walk away and abandon the party. So you're not even gaining control of the Party's resources. You'll have to build that from scratch anyway. And at that point, it's easier to just build something entirely new.
And yes, the media is a problem. But that's always been the case.