Let' be realistic here, even if they would have the same number of transactions as BTC, doge fees would be cheaper,
All copies of bitcoin suffer the same flaws and shortcomings as bitcoin. Under the same exact circumstances, they all act the same.
If doge was spammed attacked for 18 months where 80k transactions were injected into its mempool within seconds and size of its mempool went up 600% over its block cap, the fees would be exactly the same as bitcoin.
We have seen similar fee spikes in all copies of bitcoin that inherit its issues, from ethereum to litecoin and even useless bcash
even when its mempool was empty