I think the scientists need to be asked such questions. Is there something marvelous about the tasting ability of kidney cells of unborn babies that can’t be duplicated with donated adult cells?
The only thing “marvelous” about it is that using the same cell cultivation gives you consistent results. The same reason they try so hard to keep lab rats genetically identical from generation to generation, they don’t want next year’s test results skewed because the platform (rats) the test happened on changed some how. They probably started using HEK293 for purely convenience or cost reasons (it was there and available), but they keep using it so that all tests have the same platform. Same reason I install all the same patches on my software test machines, don’t want 2 machines giving different results for the same test.