[Avodah] Sukkos machshavah question

[Michael B. Nechamkin]

Does anyone have a thought to explain the difference between the 2
mitzvos of sukkos?
The gemarah adds to the mitzvah of sukkah many new halachos but they
are mostly kulos (I.e. Dofen akumah, rov, levud,etc). Conversely, lulav
and esrog also have many halachos, but they are chumrohs (chaser,
chazazis, etc). For example, the gemarah tells us we only need rov
schach/tzel for a kosher sukkah, but if even a mashahu is missing from
an esrog, it is pasul.