The corporate pop model of creating stars and hits, commercial radio since the 80s playing the same 5 tunes on constant repeat all summer long, and most of consumerist attention span being shored up by media conglomerates ––––– These are the actual factors which contribute to everything sounding more the same today than before, not "multi-culturalism".
https://www.intellectualtakeout.org/article/tragic-decline-music-literacy-and-quality
"The results of the study revealed that timbral variety went down over time, meaning songs are becoming more homogeneous. Translation: most pop music now sounds the same. Timbral quality peaked in the 60's and has since dropped steadily with less diversity of instruments and recording techniques. Today’s pop music is largely the same with a combination of keyboard, drum machine and computer software greatly diminishing the creativity and originality"
"Multi-culturalism" itself is both conducted in a fraudulent way, under the auspices of Eurocentrist cultural establishments, as well as on a microscopic scale of what it is purported to be. There are literally thousands of new music developments in Africa alone, never mind the vast ethnic groups in Indonesia or Peru or China, which the Western consumer has zero idea about. South African electronic music had been thriving for 20 years before Europe even knew it existed.
Typical African beat patterns are finally becoming more popular in Europe and the US, but the process is entangled with the corporate model of music manufacturing and distribution. So you have pop dance artists mining cliches and creating "trends" based on superficial mimicry. The problem is not with "Multi-Culturalism" LMFAO.
These guys are only one of countless different local street sounds happening in Tanzania at the moment, randomly "discovered" by some friend of mine, released globally with a video on Youtube:
The world is much more vast and varied than your provincial English brain can imagine.