Yes, Make sense, but you forget that when the altcoins recede in relation to bitcoin, you get more bitcoins and if the price of bitcon is very high, then you will have a lot more profits. Is a risk that you run because it requires a lot of patience and depends on the development of altcoin, but if it is a good project you will have a lot of profit in the long term
I do think it's even a much bigger risk than you have outlined here exchanging bitcoin for altcoins in expectation that price would rise. I tell you it's better buying bitcoin at ATH and then it crashes immediately than exchanging into altcoins. The fall of an altcoin MAY be the end of that altcoin!
As for the USDT pair, I don't trade it. I only use it as tether to hold any trading pair I suspect could dip.