This is the first (and probably the last) Guardian post I will upvote. Eat yourself, go ahead! Eventually the Guardian will realize who ran the slave trade, not report on it, and keep shooting themselves in the proverbial foot.
I wonder who will be getting reparations 200 years from now for this? What form will those reparations take? Will they be perhaps... in-kind?
You won't find any simple narratives or histories in earnest company as 1) there is no simple narrative to be had, and 2) the culture wars makes it incredibly difficult to discuss objectively.
To understand how twisted the discourse has become, here's a scholarly paper I stumbled across that seems to claim that the continuance of the Arab and Indian Ocean Slave Trades was beneficial by providing competition with the burgeoning Atlantic Slave Trade: https://www.persee.fr/doc/outre_1631-0438_2002_num_89_336_39... It's from 2002--culture war debates in academia typically long preceded the explosion in populist debates. Though that paper also has some solid quantitative analysis, and I'm tempted to think the framing was designed to make swallowing the proposed numbers more palatable--the range of estimates of the number of African slaves in the Arab and Indian Ocean Slave Trades is significant and people seem to get quite vitriolic about it, seemingly out of the belief one number or another has the effect of shifting culpability.
Whether that is a relevant distinction I leave up to you.