A large amount of Voyager 1 & 2 's success isn't just technological it is the ability to take advantage of a specific planetary alignment for a gravity assist [1] that can only occur every 175 years [2] .
[1] https://en.wikipedia.org/wiki/Gravity_assist [2] https://en.wikipedia.org/wiki/Voyager_1#/media/File:Voyager_...
Fingers crossed, if we manage not to blow each other up until then, we have 126 years to go till we can try again.
You might enjoy "A Canticle for Leibowitz" on this topic.
https://en.wikipedia.org/wiki/A_Canticle_for_Leibowitz | https://openlibrary.org/works/OL2626638W/A_Canticle_for_Leib...