Mine are usually good for a main character in a 5 minute film, sometimes a second 5 minute film. Generally the foam latex would start to age before the wire armatures gave out. I suppose with silicone the wire would go first, but I have mostly just made silicone heads and none of those have broken their wires yet.
Here is how I make a human type puppet with a wire armature: https://www.youtube.com/watch?v=MbF6m3BeGUQ
He's about 11 inches tall. I used 2 strands of 3mm (1/8th") wire in the legs and spine.
One thing that's important is to make sure there are no nicks or scratches in the wire, near where it will bend at the joints. They make a weak point where the wire can start to open up and break. So I do all the bending and shaping with my hands, not with pliers. I only use the pliers to cut the wire.
Another is not to restrict the bending area to too small an area, like only 5mm, try to give it 12mm (1/2") if possible so the bending can spread over more wire.
For joints that mostly bend in one direction, like ankles and knees, I prefer to leave the 2 wires side-by-side rather than twisted, so when bending one doesn't end up on the outside of the bend and get stretched. For the spine I do twist the wires, but lightly.
With very small puppets, like 3" tall, I did often have a problem with the wire breaking at the ankle, just where it came out of the metal foot block. I had to bend really close to the foot so it looked like the ankle bending, not the middle of the shin. So they usually didn't last long, but since they were only smaller-scale stand-ins for bigger puppets, that wasn't a big problem.