It is always better for governments and politicians to tackle problems they can do something about. Turning themselves into bad historians to posture about long past evils is pointless.
We can all condemn the eighteenth century slave trades. If we do it helps to remember not just the European slave traders that profited from evil, but also the African leaders who sold people to them. The Barbary pirates raided English towns and attacked English ships to enslave English people. We also need to remember the crucial role played in the nineteenth century by the U.K. Â in abolishing much of the trade. The Royal Navy enforced new laws against it.
The problem with the past is it teems with slavery. The Romans relied on slaves  and enforced their imperial government on subject peoples like the English with a brutal army. The Normans killed our King and imposed serfdom on many English people, stealing the lands from their English owners. No one suggests these wrongs can or should be tackled by compensation or apologies.
The past is a foreign land no one can revisit. We can study it, learn from it and seek to understand it. We can also all agree slavery is wrong. That should lead us to tackle it now in our world.