don't you need to sit down as a family at some times, to bond, to talk, hear about each other's day?
I rarely cook without at least one kid hanging out, chatting, helping cook. We chat on each others beds at night, or when we're walking, when we play board games, or just all the time. We don't need the dinner table to chat 
how do you teach your dc normal dinner conversations, manners and eating habits if they never see adult interactions at a dinner table?
Maybe my children are geniuses but this has never been a problem 🤷♀️ maybe other kids need daily table exposure to keep these skills fresh, but mine seem to be ojay with a few times a month. They can make good chat, great table manners, are mostly good eaters, confident in restaurants can differentiate between different expectations in different places and adapt.
when you are hosting do you just hand out a plate and your guests can fend for themselves where ever they can find seating
No
why would we do that?
We switched from table to sofa a couple of years ago. I bloody love it. We always have a TV series on the go: crashing with my tweens at the end of the day in front of Brooklyn 99, Stranger Things and The Middle is so enjoyable.
My mum is an amazing cook and we had some great times eating together when I grew up. However, the dinner table was also often where the worst of the rows happened, which was a real shame as my mum worked so hard to feed us well.
DH just associates the dinner table with stress - his dad was super strict about table manners and meals were to be eaten fast with only limited talking. Its taken DH a long time to chill out at the table - even now I can see him losing his mind if one child is chatting so much that little food is getting eaten.
We both had loving families and Happy childhoods, but neither of us particularly associate eating at the table with an ideal of family life.
However, I genuinely love our sofa tv dinners. There's just a lot of warmth there.