Bitcoin is not the only cryptocurrency, and not all cryptocurrencies are based on a blockchain data-structure.
There are other currencies which are not-inflationary, trustless and decentralized, and many more currencies with various levels of those properties, some are more centralized and require trust in a few in various ways, and some are decentralized trust-less but still inflationary.
There is even cryptocurrencies which do not use Proof-of-Work, or Proof-of-Stake, or Proof-of-Anything - but still can reach consensus in open distributed network.
There are other currencies which are not-inflationary, trustless and decentralized, and many more currencies with various levels of those properties, some are more centralized and require trust in a few in various ways, and some are decentralized trust-less but still inflationary.
There is even cryptocurrencies which do not use Proof-of-Work, or Proof-of-Stake, or Proof-of-Anything - but still can reach consensus in open distributed network.