This doesn't account for DIY unbranded PCs which is a superset of PC sales. There are probably about 100 DIY PCs or maybe more sold for every Mac. Up until recently demand for the DIY PCs for the last two years has been so high that it drove valuation of PC components like GPUs up to ~3x msrp. Demand is starting to taper off because transitional period to next generation GPUs and CPUs. Tempted by current Nvidia GPU prices at near msrp but going to wait for next generation RTX4000 series which usually doubles performance with every new generation.
Alternate causality played a much bigger role than "DIY" PCs. Because crypto mining platforms were so heavily reliant on GPUs, crypto miners were snatching up the cards left and right. Couple that demand with the production issues related to COVID, and it was a perfect storm that drove up prices for computer components across the board, not just videocards. The ratio of DIY PCs to Macs is nowhere near the 100:1 ratio you claim, because that would necessitate DIY PCs comprising the bulk of the PC market rather than prebuilt machines.
https://www.pcmag.com/news/pandemic-may-be-inspiring-more-americans-to-build-pcs