Here is a nice comparison between the system sizes of the PS5 and a CD-i 220. For many wo have a PS5 in their hands will wonder if consoles keep getting bigger: The same counts for CD-i: The original CD-i players were built like hi-fi component models so they could be combined. After a few years, Philips was able to create smaller models as well. Components get cheaper, designs were simplified and there was just demand: In the first years of the CD-i one of the critics reviewed that the design was very bulky, especially compared to the (at that time) competition. Chances are high that Sony will eventually release a smaller model of the PS5 as well and hopefully they will return to a design that is stackable! One of the key benefits of the CD-i design in our opinion is that it is stackable. The CD-i design after all, was not that bad and it would still hold up these days!
[Thanks, Whiteflea, Lorange27]