The vast majority of applications for AI/ML can be done with libraries, just like the vast majority of programmers doesn't need to understand how to make a compiler or even how memory works. It just helps.
At some point you need to explain why something works.
A random 40 y/o programmer might be rusty on it, but it's not going to take very long to pick it all up again.
And if you've done any game programming even just for fun, you probably know quite a bit of that already.
I definitely use a lot of statistics daily. I do not need to compute integrals by hand or construct formal proofs, but a lot of intuition is necessary.
Statistics is very tricky by the way. It is so easy to have incorrect assumptions and totally misapply the methods. Also another problem with ML in general is that if you make an error you very often do not notice it. The methods will usually work a bit worse but they will still kinda work.
Just yesterday I discovered a tricky feedback loop that corrupted my data for several weeks.
I think this why HR hire computer engineers instead of statisticians when it comes to ML.