What is Ether's Value?

Hey crypto amateur here,

I'm trying to wrap my mind around why ether's value will increase with greater adoption, application and utility of the Ethereum block chain. I'm struggling to see how ethers value as a currency or commodity (gas) relates to ethereums value/utility/adoption as a platform. If it is just because ether is needed for gas than isn't it actually devalued when ethereum becomes more efficient and gas prices go down? If it's main utility is just as a store of value from a decentralized source isn't bitcoin a better bet? Thanks to anyone who takes the time to answer this, I really appreciate it.