Once LO is out of the bouncer stage (I'm not really sure when that is?) and he's able to sit up a bit more, is a baby seat necessary/helpful? I like taking him around the house with me and plopping him down while I do chores and whatnot, but I'm realizing he'll probably outgrow the bouncer soon (he is 4 months) but don't necessarily want to just plop him on the floor.

Is there a baby seat you'd recommend, or are those in the category of "something new parents think they need but you don't"? To clarify, LO can't currently sit on his own (without collapsing on his face).