I've made the exact same point about Bitcoin for a few years now.
The bigger a market cap gets, the more it takes to double the value (obviously).
If one can find the low cap coins that could eventually succeed, the chances to 10x, 20x, or more are definitely possible, but the days of seeing 10x returns on Bitcoin over any span of time are all but over unless it massively crashes...
This is an awesome example of the power of altcoins, and I'll be including this post in my latest edition of 'Rogue Curator' 🚀