By one count I have 68 small robots and the component parts* for at least 20 more. Some of these are obsolete and others soon will be**. I try to counter this to some degree using reconfigurable designs* but this can increase the costs involved*** and so is not a universal solution.
* For example LEGO, Meccano, Vex IQ, Vex EDR, Raspberry Pis, etc.
** For example LEGO RCX, NXT, Ev3, early Arduinos, etc. The LEGO Technic cables from my RCX Mindstorms sets are actually disintegrating due to age.
*** Hacking toys, for instance, can be cheaper. See my blogs of 1 March and 7 April 2025.