where, sure, if you break it over more than one line, yes, then you need it.
I think the original intent was that bitbake.conf defines the basic PROVIDES/DEPENDS and then the recipes adjust as needed.
As such, PROVIDES and DEPENDS would then always use +=.
Unfortunately over the years this has gotten lost and bitbake.conf and base.bbclass had to become more inventive about how they set the defaults for the variables.
As such, I think += actually makes sense but I realise that isn't the way most recipes work now. We could try and fix that but it does seem like a marginal gain when there are bigger issues.
oh, i wasn't suggesting any sort of massive cleanup; i just wanted to make sure i was explaining it properly to any potential students to make sure they appreciated corner cases like this.
