Dogecoin has only one advantage: Elon Musk tweeting. If Elon Musk loses interest in Dogecoin so will everyone else. Cardano on the other hand has a whole team dedicated to marketing Cardano and improving it.
Why would choose if you could actually had both? Diversify if you are in torn between these two but basing only purely in potential in terms of technicalities then i would definitely choose up Cardano than with Doge but since there is some hype surrounding with that meme coin then you dont like to miss out the opportunity on making profits on a short time then you can always opt in to make some risk on buying it but of course you should expect that it wouldnt really go into the things you do anticipate so better watch out for that but if you are really in torn between the two then its better go
for 50-50 allocation on both coins so that at least you wont really get confused on which one you would be choosing.