good critical post. Political it es kind of undemocratic because of the mining cartells and bitstream
plus the secondary markeds aka bittrex, kraken an so on are fully centralised.
but actualy in network terms it is distributed (far more than just decentralised), this creates redundance of a single node. After OSI it does not run on the internet. TCP/IP is the Base of big Parts of the Internet and of Bitcoin
and now there will be next layer aka off chain operation aka ligthnin network ...but as you said...people choose so because they are not running full nodes
Well I'd kind of reserve my opinion on decentralization. I am getting concerned about all of these cyber attacks and given how many people use closed source OS, this could impace the security of the node system.