To be fair, it’s not as though the Red Cross has actually tried. Compare to the Nazi era, when the Red Cross regularly visited Jews and others in the concentration camps, and even delivered care packages to the residents, without having any impact on their treatment or survival rate whatsoever. One can see how they might feel there’s no point in similarly wasting their time now, even though that’s a key point of the hostage negotiations, and even just proof of life would be useful to the Jews.
[IsraelTimes] While both Israeli and US officials have insisted that the ongoing truce deal between Israel and Hamas
...a contraction of the Arabic words for "frothing at the mouth",...includes a clause requiring the Red Thingy to visit the hostages who have not been freed by the fourth day of the temporary ceasefire, no such visits have been reported.
The Red Thingy has repeatedly refused to confirm that it has been notified of this clause of the truce, but insists that it will visit the hostages if both parties agree that it should.
Hamas has yet to publicly confirm having agreed to such visits and has never in the past allowed the Red Thingy to visit those it has kidnapped.
Asked whether the Red Thingy has been able to visit the hostages, a spokesperson for the humanitarian agency refers The Times of Israel to earlier statements asserting that its staff would do so if both parties approve.