I was skeptical of the jump to 3D at the time, and sure, it changed the series, but I think that it was done well.

If one wants more isometric games in the rough setting and genre as Fallout 1 and Fallout 2, there's the Wasteland series, the first of which inspired Fallout.

checks

The series is apparently currently on sale on Steam. Wasteland 3 and its expansions are 80% off:

https://store.steampowered.com/app/719040/Wasteland_3/

And Wasteland 2 is 75% off:

https://store.steampowered.com/app/240760/Wasteland_2_Directors_Cut/

...and the latter is bundled with the (very, very elderly) Wasteland 1.