For those wondering why do they have to go to Chile?, I presume it's for the same reason as given here for the ELT (extremely large telescope, to be completed in 2024): The location was chosen because of its high percentage of cloudless nights and low light pollution [1] and (notably but with a lower weight of importance) the temperature is cold enough that there will not be differences in temperature between the interior and exterior of the telescope which could cause the rays of light to defract (ever so) slightly [2].

[1] https://newatlas.com/extremely-large-telescope-construction-... [2] https://astronomy.stackexchange.com/a/21413