One important difference is that modern movies that shoot in 1:43 IMAX typically shoot everything with other aspect ratios in mind. So a 16:9 home release of The Odyssey is going to be less creatively compromised than an anamorphic film from the 1980s adapted to a 1.33 pan and scan home video release.

We also have two things working in our favor for home video releases on 16:9 displays. First, 16:9 is geometrically well-positioned between 4:3 and 2.39:1, so displaying either of those pillar/letterboxed on a 16:9 screen only leaves 25% of the screen area unused. (We literally chose 16:9 because it's the geometric mean of 4:3 and 2.39:1.)

Secondly, a typical home TV now is simply much larger than a typical home TV 30+ years ago, so the reduced size of a pillar/letterboxed image is still just straight up bigger than most home TVs were prior to the flatscreen revolution.