It’s actually a plastic ribbon with a metallic foil in a zigzag pattern on top of it. It’s extremely cheap and does a pretty good job. It usually sits on top of a metal bar that can deflect a tiny little bit.
You can read all about it here: https://en.wikipedia.org/wiki/Strain_gauge
The main effect is that the resistance depends on the geometry. So as that changes, the resistance changes as well.
This is usually done to keep things going as normal as possible for as long as possible. Once people start noticing something is wrong, the best people start looking elsewhere. Before you know it, not only is the company in financial trouble, but it can’t recover because some of the best people left. At least one time I witnessed, the company was working on layoff plans and even limited bankruptcy, but at the same time negotiating with the investment firm that owned part of the company to get more money. If they got the money, everything would be fine. It wasn’t till that fell through, they had to start laying people off.