Does anyone travel with just an under seat carry on?

Does anyone travel with just an under seat carry on? I’m going to wedding soon and flying Frontier. My only electronics are my phone and my over ear headphones, and I’ll bring mostly dresses (easier to wear in the heat) on my trip, plus makeup and toiletries. Does this seem doable? Not too worried about price of backpacks, more concerned about if this is a feasible option.