You only pay capital gains if you sell your crypto for U.S. dollars.
Not stable coins, but actual U.S. currency.
As long as you stay within the crypto ecosphere, you're not paying any taxes at all.
Meaning, if you've got a 5% yield on whatever crypto you're holding.......as long as you take the yield in crypto and don't sell it you won't be taxed.
So, basically, with any crypto and/or yields........you're good as long as you don't sell.
Converting is better than selling.
Now, in terms of selling, you're right.
You only get taxed on the difference between what you sold it for and what you bought it for.
Meaning, if you spent $1,000 on some crypto............and sold it for $1,500........you're only taxed on the $500 you gained by selling it.
Not the entire $1,500.