There will be about 100 people at my wedding. It will not be a super formal affair.
I would like to let people sit where they want to for dinner. I don't like being told who I have to sit next to at events, and quite honestly I don't want the headache of making these decisions.
I believe there will only be one or two people who doesn't at least casually know other guests. Many of the guests are in my parents' social circle or are part of a larger group of my and my FI's circle of friends.
Is it ok to just let people sit with who they want to? Are there downsides to open seating I may not have thought of? I'm confident that if I mention to a few friends that one or two people might be alone they'll make a point of being inclusive.
The problem with open seating is that the last people to enter the room find only a few single seats scattered around at different tables. Those last few people are likely to be those with mobility issues: elderly or handicapped people who need to sit with family or other helpers.
Imagine being in a family of five, entering the room, and finding the remaining empty five seats all at different tables.
Assigned seating avoids these issues. You don't assign individual seats, but rather assign people to tables. This ensures that your couples, families and other groups get to sit together.