Recently, there has been a genuine shortage of blood, platelets, and plasma ever since the COVID-19 pandemic. This has caused people to have to delay life-saving emergencies. This is a genuine shortage where people's lives are being affected by said shortage. Therefore, I believe it is a moral obligation to donate blood, platelets, and plasma as much as allowed by the donation center. By doing this, you are saving lives and it is pretty inexpensive and cost-effective.
Sources:
https://www.redcross.org/about-us/news-and-events/press-release/2024/red-cross-declares-emergency-blood-shortage-calls-for-donations-during-national-blood-donor-month.html
Furthermore, I talked to a person who took my blood. Can't provide a source on that, but I am guessing the person who took my blood wouldn't lie just like that.
I don't mean to be discouraging, but it would help me greatly if you added some sources to the post and/or added some explanation of how this qualifies as "probably the current most effective altruism". In its current form, I find this quite unconvincing. While I do donate blood, I don't think it's a priority over other work, and superficial googling did not convince me that it should be.
Agreed that the article doesn't provide an in-depth data analysis the provides a compelling evidence-based conclusion. It wasn't that type of article.
Importing blood from other countries as an alternative solution to donating blood doesn't make any sense at all though because the blood from other countries comes from donors too.