Was expecting to find some modern examples of such modular computer approach in comments, but am disappointed for now. Looks like Framework laptop is closest i can think of in this regard. Which is basically just USB hub for extra ports.
Another example from mobile phones which was google modular phone prototype which also failed to reach consumers.
Another example from mobile phones which was google modular phone prototype which also failed to reach consumers.
Project Ara : https://en.wikipedia.org/wiki/Project_Ara