You may not like how I presented it as a bit of a puzzle, but it isn't an extraordinary claim. What does Dash have that would support a higher price/cap:

1. Does it have more development as evidenced by github metrics (commits, etc.)?
2. Does it have more more discussion on neutral forums such as reddit/twitter/etc.
3. Does it have evidence of more transaction usage outside of investors?
4. Does it have more trading volume?
5. Does it have more available liquidity on order books?
6. Is it primarily traded on a different/better exchange making it accessible to more/different investors?
7. Does it have better search rankings (have to be a bit careful here to not find detergent ads, etc.)
8. Does it have more coverage by journalists, including bloggers, podcasts, etc.? (Especially unpaid coverage.)
9. Does have more/better recognition for soundness by influential technical experts?
10. Is there evidence of new users joining the community at a higher rate?

The answer to all of these is no. The two are either comparable or Monero is stronger.

Now if you ask why the price/cap is what it is, the obvious answer has to do with supply dynamics.

Let's not forget that until recently Bytecoin was also ranked higher than Monero for a year or more, at times quite a bit higher, while at the same time failing on most or all of the above metrics along with others. Those of us looking at the fundamentals said the very same thing -- that it was where it was because of supply dynamics, not fundamentals. Sure enough Bytecoin is now at about 1/2 of Monero's market cap, and was recently much lower than that.

Obsession with market cap (and cap ranking, price) as a particularly meaningful indicator of anything is a blind spot of many crypto investors. Don't be blind.