During the crypto bubble the miners often used regular gpus, sometimes with firmware modification for undervolting that were easily reversible. But we are not in a crypto bubble now, I'm not sure where gp is coming from with that comment.
In the last year bitcoin is over 200%. Litecoin is almost over 100% (in fact, since April it is over 200%). I have no horse in this race, but I am not sure I would call it "not a bubble".
I was under the impression that no one bought GPUs for mining anymore in general, as it's a waste of money compared to specialized hardware. During the last crypto bubble I noticed a lot of regular people building mining PCs, this time I noticed nothing of that sort. However, https://www.notebookcheck.net/New-financial-analysis-suggest... suggests I might have been wrong about that.