There's no fundamentals behind it
Actually, as far as cryptocurrencies go, Dogecoin has great fundamentals:
- strong community worldwide
- 1-minute block times
- $0.01 tx fees (or less if you're stingy)
- merge-mining with LTC makes network more robust
- plentiful supply makes it easier to use as a currency
I'd argue that, as far as acting as a currency goes, DOGE is superior to BTC or ETH. Its far cheaper to send, and now that its been around for 10.5 years, its firmly entrenched in the crypto landscape, which means its widely accepted compared to most other cryptos.