No it isn’t, because the way DNS work.

• you ask your dns server if it knows the adres for some website.
• if it doesn’t it’ll ask another node
• if it does, it will tell you.

So a dns server either knows the webadresses it serves, or it knows which way to point you for more info. This is a leveled arrangement, so there are some high level dns servers that basically divide the whole Internet in sections (11, if I members correctly). And they all have layers of subsidiaries, like a tree structure. The leaves of this tree know a few specific addresses, or else they send you up the tree and the node might send you down again, to a different leave.

If you would do this on block chain, you wouldn’t need the intermediate nodes anymore, but the leaves would contain all the information themselves. The leaves, in this case, would probably be a file on your computer and would basically contain the entire Internet. Anyways, the big problem with this isn’t size, but the linking. Blockchain only knows which nodes came before your node, not which nodes came after. Even if you did implement it like that, you’d have a massive list of nodes. Imagine you have an old ip address and you want to lookup a brand new website. You could possibly be sent through millions of nodes before you find what you’re looking for. The tree structure dns has now, cuts that down to maybe a dozen nodes, depending on what you’re looking for. You can actually how many nodes with traceroute, or online om dnschecker.org/online-traceroute