The only game I can think of that was similar to the model you suggest was the long ago "Spaceward Ho!" series, which was uncomplicated but fun. There was no tech tree; putting money into each of several categories of research yielded incremental improvements in that area over time but occasionally one would get a "breakthrough" that would boost that area dramatically or provide a new capability.

I thought it was an interesting idea but it seems fundamentally incompatible with having a tech tree at all.