‘ads Rarely Show Due To Low Quality Score’ - My Understanding

Can anyone give me a steer on this

I have a keyword that has 4000 impressions but just 24 clicks. No problem there, it suggests to me the advariation is not particularly relevant

But this is the bit that is puzzling me. Google is now displaying this text next to the keyword ‘Ads rarely show due to low quality score’.

Does Google see this lack of relevance (quality score) and stop showing the Advariation on that keyword?

Maybe i misunderstand ‘impressions’ i understood this to be the amount of times an Advariation is displayed. Is that right?

I suppose the reason i am a little thrown is that i read impressions as another form of search popularity for a particular keyword ie If the impression are high on a keyword then a lot of people must be searching with that keyword. If however because of the quality Score Google is simply not displaying the Ad anymore then my assumption is a little off.