The example that pisses me off (and you should be angry too as a Simpsons thread poster) is Apu no longer existing because of cancel culture. Just because some Indian guy made a documentary about how Apu was insensitive and people latched onto that to cry over Azaria voicing Apu. Azaria voiced other ethnicities too, was that wrong? RIP Bumblebee Man.
In some ways, the problem with the Simpsons isn't that Apu was cancelled, it's that the show has gone on for so freaking long that some of the foundational aspects of it don't align all that well with social views today.
A show like Friends is now taking heat for the jokes that were made at Chandler's transgendered father/mother's expense. Mainly because it's so popular on Netflix (my nieces love it) and so it hasn't exactly left the zeitgeist.
I think the reaction is a bit overblown, but I don't really have a problem with comedy evolving and adapting to accommodate changing social views.
Breakfast at Tiffany's is considered a classic, but when you watch something like this, you kind of have to raise your eyebrows. I don't think they were being deliberately cruel at the time, but by today's standards it would be regarded as a pretty racist portrayal.
Do you think you would have a one-note convenience store owner like Apu if you started a sitcom today? Probably not. Someone like Dr. Hibbert or Smithers doesn't raise as many alarm bells because they occupy positions of prominence and are less stereotypical.
Is it that much harder to defend when it's a white guy providing the voice? Sure it is. Especially if it's coinciding with greater scrutiny on the lack of minority casting in general.
There's two dimensions to the minority casting question.
(a) From an economic opportunity perspective - there aren't that many minority roles, so having white people play them is sort of a double whammy.
(b) From an acting performance perspective - there are people out there who believe that only someone of a similar background can truly understand the role that is required. I take issue with this, personally, because that's what acting is all about.
From a practical standpoint, the Simpsons succeeds to some extent because a few people can voice a huge number of roles.
But personally I think that people will relax a bit with actors playing other ethnicities once there is more balance among acting opportunities.