True, much of “Islamic finance” is nonsense.
But “unlikely to be true that interest constitutes riba” is just obviously false.
Hundreds of quotes can be brought, but Imam Malik in the Muwatta describes what is typical of any modern loan as “without doubt the essence of riba”
There is no such thing as Islamic finance, most “Islamic finance” products are either (not)clever workarounds or just fee extraction (ie not finance in function), always blowing up in the end, and, frankly, it’s just unlikely to be true that interest constitutes riba (ie usury), such that all of this effort is required in the first place.
Islamic finance is a category error sustained by identity anxiety with some anticolonial resistance flavouring (defeat the fiat New World Order and big banks!)