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.
This source helps me see that now is a time where blood donations are especially needed, but it does not give me the means of evaluating that it would be more effective than alternative courses of action. Thank you for adding it in comments and post!