Ultimately I think that Islamic jurisprudence was a product of its time and, at that time, critique of the economy in a fully-realised way didn’t exist.

More precisely, it’s that the Quran and the hadiths - the written sources - that were a product of their time. Jurisprudence - if understood as the legal theorising and interpretation being done upon prior texts - is a continuing process that’s still ongoing today, and it’s definitely here where modern forces of global capitalism have influenced modern Muslim legal theorists into moulding the orignial texts into the current industry/academic edifice that’s labelled as “Islamic finance”. So yeah, technically speaking, it’s not that “Islamic jurisprudence was a product of its time”, but “is a product of its time”: that time being present-day global capitalist hegemony. (Sorry, I’m probably nitpicking here; I know you said you want to avoid going into the weeds with interpretation and real-world application. I think I would agree generally with most of what you’ve written above; just taking the opportunity to air out and give some structure to a few thoughts that had been jangling around my head for some time.)

I’d be fascinated in hearing what a Muslim would have to say about how they think Muhammad would respond today if he saw how private equity firms like BlackRock are grossly distorting the property market and squeezing every last penny out of people who have no other options for housing available. Something tells me he wouldn’t just be like “Alright guys, this arrangement is totally fine as long as you don’t jack the rents up too high, okay?”

True, and I’m aware that there is some existing discourse/scholarship by Muslims on the Islam’s compatibility with socialism as a political movement. Syed Hussein Alatas’s Islam and Socialism provides a good overview, I think. One bit I think is particularly relevant to the concept of riba is where Alatas outlines the position argued for by Oemar Said Tjokroaminoto, who was a nationalist figure in pre-independence Indonesia; Alatas suggests that Tjokroaminoto, in trying to prevent a spilt between the Islamic moderates and radical Marxists in his party (which eventually happened and led to the the radicals joining the Communist Party of Indonesia) attempted a theoretical reconciliation of the contradictions between Islam and socialism (pg. 62-4):-

In 1924, Haji Omar Said Tjokroaminoto, the leader of Sarekat Islam, then the biggest political party in Indonesia, published a monograph (113 pages) on Islam and socialism. (…) It arose out of the need to counteract communist propaganda. Tjokroaminoto’s party, the Sarekat Islam, was seriously infiltrated by communist elements which led to a split in 1923.

(…)

Regarding state ownership of the means of production, Tjokroaminoto suggested that this was Islamic. In the time of the Prophet, the state owned and acquired land. It is interesting how Tjokroaminoto linked Marx’s theory of surplus value and its expropriation by the capitalists to Islam. The Islamic prohibition of usury, according to Tjokroaminoto, is the same as a prohibition against the immoral capitalist expropriation of surplus value.’ The reforms carried out by the Prophet were thoroughly in the spirit of socialism. The instances cited by Tjokroaminoto are the following, in his own words:

“With the law of zakat Islam intended to make it obligatory for the rich to spend on behalf of the poor. In the time of the Prophet Muhammad (peace be upon him) land was the greatest source of livelihood for the working class, and as I have explained earlier, land was owned by the state. Small industry from pre-Islamic times was run by the poor or the slave for the sole profit and welfare of the owners, most of whom were harsh and oppressive. Before the advent of Islam, those who worked in industry were extremely looked down upon by the aristocracy, while the slaves who functioned as labourers were treated as animals by their capitalist masters. The Prophet Muhammad (peace be upon him) immediately raised the status of labour and workers. Though he descended from the highest Arab aristocracy, he worked as a trader before his preoccupation as a Prophet took up his entire time. As a recognized prophet he became ‘the spiritual and worldly ruler over Arabs and the Muslim territory, but he mended his own clothes and shoes. The biggest step he took in the direction of industrial socialism was when he raised the status of the slave to that of the free man. The slaves were given rights which they never had before. The slaves were made fellow workers; they were given positions of command in the army, or to become heads of other undertakings, while in yet other spheres as in the family, they became members of the family who treated them as animals before the coming of Islam. That being the case, the slaves took part in sharing the welfare and the profit of their masters. Truly, the step taken by the Prophet Muhammad (peace be upon him) to improve the condition of the working class during his time, was unsurpassed in greatness in the economic history of the world.”

Tjokroaminoto was not blind to the fact that during the last thirteen centuries, despotism, autocracy and egoistic materialism had chiselled at the foundation of Islam. As long as the Qur’an is still with us, the ideal of democracy and socialism in Islam shall remain alive. He said: “If we Muslims truly understand and practise the teachings of Islam, we cannot avoid becoming a true democrat and a true socialist.