There is a possibility that this has been an issue in previous version (2019 etc.) but at least in Photoshop 2020 I've experienced very noticeable lagging/sluggishness with the software when I have added guides to a document. The sluggishness is present in simple documents with few layers and complex documents with multiple layers, groups and folders. Of course, the amount of lag depends on the document size but even with a 1024x2048 document at 72 dpi with multiple guide lines, the lag is very much there, affecting even the basic manipulation of the document and even simple panning of it. I can't say I remember it being like this a few years back so I'm wondering what could be the case.
Also, it seems that the ruler bars on the side of the document are more buggy than ever and even those seem to lag when panning the document.