What makes you conclude that? Do you have any data on the cost of running a full node for each network? One of the critical issues is understanding what parts you include in the word "decentralized". If you draw a conclusion just from whether you can run a full node or not, then the issue would be ambiguous since almost any coin allows you to do that. How would you differentiate between Bitcoin and other blockchains owned by some governments if the latter also allows you to run your own node then? Are you going to call them decentralized too?

I believe you can see what other factors you should consider from the answers shared above. The consensus mechanism, how it launched, who controls the repository, who can participate, and so on are one of those things. If you don't agree that those factors are important, then I guess no one can convince you that Bitcoin is more decentralized than others.