Actually I agree with you. In crypto trade, you have to stay in either altcoins or sold your altcoins and stay in BTC.
BTC is also subject to fluctuation.
Therefore as long as you get more and more btc out of the trades, you are enriching yourself despite your value in fiat could be lower.
(This could be cause by BTC dropped.)
Unless you sell your altcoins and convert it back to fiat.
(a troublesome and cost incur as well)