Sure, the 90's were a rough period for them, but I think a series of failed OS strategies and technical debt are more responsible for that than just what language they used.
You could argue that their ambitions re Swift scaling from scripting all the way to writing an entire OS might never grow substantially outside Apple, but there's also the teaching aspect to think about.
"Objective C without C" removes a whole class of problems people have in just getting code to run, and I'll bet it shapes their mind in how they think about what to be concerned about in their code v what's just noise.
This is not what Google has found, actually. Teams who wanted to use this for research found that a static language is not flexible enough when they want to generate graphs at runtime. This is apparently pretty common these days, and obviously Python allows it. Especially with JAX that traces code for autodiff
Or has at least found that existing solutions for statically typed "differentiable" programming are ineffective, and I'd agree.
But having some way to check types/properties of tensors that you are doing operations to would really help to make sure you don't get your one hidden dimension accidentally switched with the other or something. Some of these problems are silent and need something other than dynamic runtime checking to find them, even if it's just a bolt-on type checker to python.
There are a lot of issues with our current approach of just using memory and indexed dimensions. [0]
Swift was railroaded in Google by Chris Lattner, who has since left Google and S4TF is on death watch. No one is really using it and it hasn't delivered anything useful in 2.5 years