Bitcoin can also be devaluated by lost of trust. Also the current supply of Bitcoin is through mining only. If rules are changed by a fork then you will have 2

Bitcoin can also be devaluated by lost of trust. Also the current supply of Bitcoin is through mining only. If rules are changed by a fork then you will have 2 different coins. We already saw it with bitcoin cash. Another way would be that the current consensus on Bitcoin itself changes. But that's a risk. How can people then predict such a consensus change. How risky is it to have Bitcoin since the day after the rules may change ?