Great answers. However I have a few questions.
Why would the avos have had a reason to shake a lulav, or sit in a sukkah- did he wander for 40 years in the desert? Many mitzvos in the Torah are experiential, or at least performed based on previous experiences- e.x. Sukkah, the Seder, etc. many mitzvos asei are given because bnei yisroel were avadim in mitzrayim. How could the avos have performed those in the way they’re intended with proper kavanah?