Fair point. Last time I took that train (mid 1990s) it didn't run to Pontiac or Troy, and I recall there being very infrequent service. A far as I know, it's not the major mode of passenger transit between Detroit and Chicago. Cars are. That might be because of the serious lack of last-mile transit connectivity in the Detroit area.
Cars are definitely the major mode. Lots of quick flights, too.
They’ve made a lot of investments since the 1990s. It’s much improved, though perhaps not as nice as during the golden years when it was a big part of the New York Central system (from the 1890s to the 1960s they had daily trains that went Boston/NYC/Buffalo/Detroit/Chicago through Canada from Niagara Falls to Windsor).
During the first Trump administration, Amtrak announced a route that would go Chicago/Detroit/Toronto/Montreal/Quebec City using that same rail tunnel underneath the Detroit River. It was supposed to start by 2030. We’ll see if it happens.
