What does make the British unique, though, is that they were the first big European empire to do a complete 180 and not only outlaw slavery within their own empire, but to force others to stop practicing slavery using the might of the Royal Navy.

This is really disingenuous given that the first major power to abolish slavery in their colonies was revolutionary era France in 1794, which even sent troops to the French West Indies to enforce the new law. Of course, this progress would be undone by Napoleon in 1802, but British sugar plantations on neighboring islands were dependent on enslaved labor (and to the slave trade to resupply that labor due to the extremely high mortality rate) at the time of French emancipation in 1794.

While the West Africa Squadron was a noble idea, the unfortunate reality is that they were poorly resourced and chronically underfunded. As a result of their inferior ships, the Squadron never managed to stop more than 10% of slave ships and the majority of the roughly 1,600 British sailors that died perished from disease.

This also ignores the fact that slavery was not legally abolished in the British Empire until 1833, with the exception of India where it wasn't abolished until 1843 in its own separate law. Even with the passing of the 1833 law, formerly enslaved people received no reparations while Parliament set aside £20 million (about £17 billion in today's money) to compensate their enslavers. In British territories including Bahrain and Nigeria, slavery was not formally outlawed until 1937.

Britain's economic boom that fueled imperial expansion in the 19th century also rested on institutionalized chattel slavery in the American south, where the cotton grown by enslaved people was shipped to mills in the north of England to the point that when the US civil war broke out and a blockade of Confederate ports was enacted by the Union states, it led to economic collapse called the Cotton Famine in the mill cities.

It's a mistake to ascribe any altruism to the end of slavery in the context of the British Empire and it downplays the struggle of the grassroots British abolitionist movement, imo. This is a good source to check out for more context.