[Question] Why do humans not have built-in neural i/​o channels?

Com­mu­ni­ca­tion be­tween or­ganisms of the same species is of­ten benefi­cial, for a va­ri­ety of rea­sons: shar­ing in­for­ma­tion, sig­nal­ling, bond­ing, etc. Yet cur­rently the most ad­vanced form of com­mu­ni­ca­tion to have evolved, hu­man lan­guage, is still very low band­width com­pared with the amount of men­tal pro­cess­ing our brains do.

It seems con­ceiv­able that our ner­vous sys­tems might have evolved ways to di­rectly (tem­porar­ily) in­ter­face with each other and ex­change a large amount of in­for­ma­tion. For ex­am­ple, re­tractable bun­dles of neu­rons that are spe­cial­ised at quickly form­ing con­nec­tions with their coun­ter­part neu­rons in con­speci­fics.

1. What is the main rea­son that this has not hap­pened in any large an­i­mals? If evolu­tion had con­tinued with­out hu­mans “tak­ing off”, we would have even­tu­ally seen such neu­ral links in some an­i­mal species?

2. What’s the clos­est thing to this we see in any species?