Is cleos the most trustworthy wallet like how bitcoin core software is to bitcoin?
Let's see the definitions of the two softwares.
From eos developers guide: cleos is a command line tool that interfaces with the REST API exposed by nodeos.
From wikipedia (the best description i can get): Bitcoin Core includes a transaction verification engine and connects to the bitcoin network as a full node.
From this description, bitcoin core can be seen as
nodeos) is developed by block.one (eosio) so it should be reliable...
cleos is not a wallet software; it's a CLI tool interfacing with nodes and wallet services.
EOSIO software is akin to Bitcoin Core, which comes with
bitcoin-cli. These are comparable to
cleos, respectively. So, if you want to draw parallels with other blockchains,
cleos is somewhat similar to
bitcoin-cli in Bitcoin Core or with
geth in Go Ethereum.
Perhaps the diagram below from the documentation may clear up how those tools interact with each other: