Companies and groups and projects make their own designs to suit the blockchain technology ideology. So choosing one image might even lead to a copyright issue depending on your purpose of usage. In my opinion any image representing a connection of "blockchain-related" devices, nodes, ideas, etc can represent the blockchain.
You are absolutely right. Everyone creates his own image of the blockchain.
Just as in the beginning there were variants of the bitcoin sign.
And often it is BC.
“ The Bitcoin sign is part of Unicode 10.0 (released June 2017) with code point U+20BF (₿). As of June 2017, font support for the Bitcoin sign is in macOS Sierra, iOS, Android O beta, Windows 10 Creators Update and several Linux releases. After being rejected in 2011, the Bitcoin sign was accepted for Unicode in November 2015 and first appeared in Unicode 10.0 in 2017…”
I'm unfortunately not a designer to develop a symbol of blockchain.
But someone from the community is an artist.
I would like to discuss the idea of a symbol and someone will suggest an interesting option.
If he likes it they will use everything. After the changes with each use, a common and common symbol can be born.
Without limitation and copyright.