To go together is to look or taste right in each other's company. Those colours go together, cheese and wine go together, they go together well.
It also means to be a couple, which is a slightly dated use, and to occur as a pair, so poverty and poor health go together. The judgement is about fit rather than about quality.
1phrasego togetherTo look or taste right in each other's company.
“Do you think this red tie and green shirt go together?”
go together is a matching.
Go plus together, from Old English togaedere, meaning into a group.
See go and together
Etymology from Wiktionary, CC BY-SA
Practised in Phrasal Verbs