I do find it plausible that those interventions (or other longtermism/​x-risk/​GCR-related interventions) save lives in the present generation more cost-effectively than GiveWell top charities do.
That said, I think the following posts provide useful arguments for being skeptical about claims like the claim that those interventions save live in the present generation more cost-effectively than GiveWEll top charities do:
I do find it plausible that those interventions (or other longtermism/​x-risk/​GCR-related interventions) save lives in the present generation more cost-effectively than GiveWell top charities do.
In addition, a substantial chunk of my 2020 donations went to ALLFED (though this was motivated by longtermist rather than near-termist considerations).
That said, I think the following posts provide useful arguments for being skeptical about claims like the claim that those interventions save live in the present generation more cost-effectively than GiveWEll top charities do:
Beware surprising and suspicious convergence
Why we can’t take expected value estimates literally (even when they’re unbiased)
(I think I disagree with parts of this post, but can’t remember precisely how, and I definitely also think it makes useful arguments)
(I’m not necessarily saying I disagree with your claim; I just think it seems useful for these or similar links to accompany that claim.)