Why is consummation of a marriage when very young permissible when pregnancy at young age carries high risks and dangers?

https://shamela.ws/book/11430/18980#p1 This link talks about the following: - The Malikis and Shafi'is say that when a minor is able to withstand intercourse this impediment is removed. - The Shafi'is say that if the husband says 'hand her over to me and I will not have intercourse until she is able' even then she will not be handed over to him, even if he is trustworthy. That is because there is no reasonable security from his lust. Medical research discourages pregnancy at very young ages e.g. 9, 10 and 11. However, Aisha was married at 9, an age considered very young for pregnancy. Scholars tend to focus on the dangers of sexual intercourse rather than pregnancy itself. How can coitus be permissible with a very young girl but the dangers pregnancy which can follow, were not discussed by them? Regarding the marriage to Aisha, since we have more medical knowledge of the dangers of very young pregnancy, would marrying someone of that very young age be forbidden and objectively wrong today, since the shafis said if you fear harm for her then the hand over cannot happen? I'm asking as angel Gabriel essentially passed the message to marry her from God. I have seen related Qs on the site but this is a bit different. Thanks.