These are valid points, and I must stress that CVD is nowhere close to being in my wheelhouse - I can overstep here easily. From the bit that I know about prospective trials of those sorts, participation is often driven by a single factor; physician links to the study which biases towards university affiliated clinics. I have no doubt that impacts patient recruitment.
As the article states there has been a directive since the 1990s for clinical trials to reflect the racial and ethnic proportions of the real-world populations impacted by the condition. That has met with some (limited?) success. The guidance has strengthened in the last few years.
These issues are well worth discussing. My point was that the article seems to be focused on awareness raising with a confrontational edge. The research field is well aware of these biases and has been taking steps to correct them. I didn't see that sort of nuance in the article.