i don't think that Doge coin will ever die because of its community but at the same time it does not have the potential to grow. not because of lack of innovation or starting as a joke, no the biggest reason for that is the fact that there is 103 Billion Doge created and is being created each day.
I notice this argument about the 100 billion supply coming up every now and then, but I don't think it's valid.
What matters to investors is the market cap, and more specifically, the change in the market cap over time.
The average number of coins bought and sold in trades is a cosmetic issue, and actually it could be argued that it's better to have something like 10K doge rather than 0.005 of a unit of currency, because people in general aren't very good with math, in particular when it comes to decimal values less than one. Maybe if the supply was in the trillions or quadrillions, then it could have a negative impact due to the annoyance of dealing with very large numbers for small values in dollar terms, but in the current state it seems to be more of a positive.
5% is not bad considering the rate of growth in cryptocurrencies, ETH has a higher inflation rate and that apparently didn't stop the hordes of buyers. It could be changed to a lower value like 2% in the future if necessary.