It might be machine learning stuff which heavily leans into nvidia hardware
In general, the market share (as in GPUs sold, in total, for all systems, not just Linux) was around 70% Intel, 17% Nvidia and 13% AMD. This was before GPUs turned into inobtaniums, so I guess Nvidia and AMD didn't improve their positions much.
Yes, there are ML guys on the Linux side, but that could be compensated by gamers on the Windows side, so I assume that if anything, Windows would have more share of Nvidia than Linux. Miners don't really care for desktop.
There is a place where Nvidia achieved significant share - it has 70% in Steam hardware survey. That is to be expected, gamers are heavily biased towards Nvidia.