If muscle-building is your intention, these two are basic. However, they are also basic to just maintaining physical sturdiness and functionality. Yes, at heavy they are difficult and unpleasant. It's not for fun, really.
I only do one set of 6 of each weekly. Or weakly. Not body-building, but it is body-maintenance. I do increase the weights periodically so I am not going backwards. I find the barbell squats more challenging, and appreciate having a spotter behind me when I approach my limit. With deads, of course, you can just drop the bar if you have to. I love the sound of dropped barbells in the morning.
Deadlift vs. Squat: Muscles Worked, Benefits, and Strength Ratio