The miners’ profits depends not only on the price of Bitcoin, reward size and fees, but also on the electricity prices. With lower Bitcoin prices, some mining rigs may become unprofitable, and a good indication of this is found on asicminervalue.com. If too many miners are unprofitable and have to close down their rigs, it may compromise the security of the network, although this seems quite unlikeable with the current rewards and fees – read more on this here.
The number of applications for crypto technologies is an important component in the adoption of cryptocurrencies on a global basis. A major application for smart contracts is within Decentralized Finance – bank-like services such as lending, but run on a blockchain instead of having an intermediary bank. One measure of the use of these applications is the Total Value Locked in the applications: