All of our rental tables have them, it helps tremendously when seating players with 6+ tables, and for moving players around. "Sir, can you please go to red table, seat #3?". We hand out seating cards to players which is our business card with a Table # and Seat # on the back side.
In a home game setting, it's not as useful but still can have it's purpose. If you don't have the same number of players as dedicated seat numbers, just ignore the numbers, or players just figure out where to squeeze in.
View attachment 1285862