The studies provided do not concern blood donation and therefore offer no point of reference for assessing whether donating blood regularly is good or bad for the health of the donor. This question cannot be answered substantively without exceeding the limits of the available sources.
The available research sources contain no information about blood donation and its effects on the health of the donor. The studies provided concern entirely different topics: creatine supplementation, artificial sweeteners, and a hepatitis B treatment. On the basis of these sources, therefore, no substantive statement can be made about whether donating blood regularly is healthy, neutral, or harmful.
Because the question is not covered by the available scientific sources, it is not possible to give an honest answer without going beyond the source texts. That would mean fabricating or introducing information that cannot be verified, which is contrary to the principles of this publication.
If you want a reliable answer to this question, it is advisable to look for studies that specifically address the health effects of repeated phlebotomy (blood-letting) in healthy donors, such as research into changes in iron levels, blood pressure, or cardiovascular risk. That information is not contained in the current sources.
The three studies provided (PMID 39720835, 35285920, 40714040) concern creatine supplementation, artificial sweeteners, and hepatitis B treatment, respectively. Not a single source addresses blood donation or its health effects in donors.