What's lost if we switch to basic family plan?

I see audiobook listening is but what else is?

Do any of the following change:

Audio quality

unlimited skip

Offline Listening

Addfree listening

Individual vs family

Besides sharing an account with the family is there a difference? In Premium Individual I was able to listen and download some books but now I just got Premium Family and it’s got this message:

You can't buy audiobooks in the app, but titles you've already purchased through Spotify can be listened to here.

In individual the lock icons weren’t on any of these chapters - what am I doing wrong?

Don't forget to switch to basic family with the price increase if you're the account holder and not using audio books!

Back to $16.99USD on basic... For now.

With the price increase, it looks like I can keep the $16.99 price by going from premium family to basic family. There are two differences listed: basic doesn't include audiobooks (fine), and there's a distinction between "up to 6 basic/premium accounts".

So does basic family include ads? Doesn't allow downloads? Anything else? If so, what is the benefit of basic family over just going with the free service?

for context, we are a family of 4, 2 daughters, me and my wife. we share a premium individual account across 4 devices, then i bought my daughters a tablet and they installed spotify. and now one of us gets logged out from time to time, is it true only 5 devices per account? then i saw the family plan, with 6 accounts all tied in, does that mean we can log in 5 devices per account? and also can we import and export playlist? since my account holds all our playlist.