Serving a full Thanksgiving spread by yourself is a challenge even for an accomplished chef, yet many non-cooks seem to think it's totally normal.
It's not that each separate component is necessarily that complicated; it's that timing everything correctly and knowing what to prepare in advance so that everything lands on the dinner table warm and ready is a logistical feat that is enough to overwhelm anybody. Add to that the astronomical cost of groceries and the time it takes to prepare a home for hosting, and it is kind of crazy to think of the number of people who expect that a designated female relative is going to be able to do it all single-handedly.
For this very reason, it is not uncommon for guests to help out whoever is on hosting duty with their own contributions. Maybe they cover the drinks, help clean the house, or bring a side dish or two. This holiday is all about being thankful for what we have, and that is much easier to do when people share the burden of the preparations, even if people aren't going to their house.
When it comes to the arguments and drama that tend to crop up around this time of the year, a lot of them revolve around one individual feeling like they are expected to do too much just so their family gets to enjoy themselves and celebrate. Unless you are explicitly told otherwise, it is pretty selfish to assume that one person can handle all the Thanksgiving preparations by themselves.