This is a big question tbh and the lack of a succession plan is a function of many things:
1. This was my dad's baby. He loved the engineering and the science of it and so the idea of retiring from it was difficult for him to conceive. Doing that also requires thinking about one's mortality which I also believe was difficult for him.
2. This was a small market business in a tier 2 city in India. Attracting talent that could take it over was challenging. And myself and my siblings having been born and brought up in the States and being utterly clueless about the engineering/science of the company made us a non-starter.
3. As others have pointed out, he was thinking about succession/exit because he knew it was required for the biz to live on and grow. But life unfortunately had other plans and he was taken away from us unexpectedly.
There are definitely lots of could haves, should haves, would haves, etc I've thought about afterwards, but this was clearly one of those "play the cards you're dealt" kind of situations.
Thanks for reading.