They are robust. They make them commercially that way. I had one in a piece of equipment. In another piece, they used a differential pressure sensor. The cost was well over $100 and it had to be replaced. An air velocity meter which uses a thermal sensor got dirty and required cleaning, Cost was well over $500 - $1000. One system had a readout and the other didn't, hence a failure meant you had to clean it or some other problem. With the readout, you could proactivley clean it.
Trust me, the vane and microswitch is more robust. It's just a lightweight piece of metal with a small piece of wire attached to it and the microswitch lever in the exit air stream.