I don't actually have a complete count, but it's a lot. When you maintain a Warhammer habit for a couple of decades you tend to wind up with a lot of unbuilt and unpainted stuff in boxes uncatalogued, alongside many hundreds of painted miniatures packed away in cases and army transport boxes for travel to and from tournaments, plus of course some nice painted stuff on display, but I don't even have a count of those right now.
Full Warhammer armies for Wood Elves and Chaos Warriors painted, plus partial forces for Beastmen, Skaven and High Elves painted, plus some unpainted for Tomb Kings, and misc unpainted figs for all of those factions. Full 40k armies for Dark Angels, Eldar, Chaos Space Marines, and Blood Angels painted, and some Chaos Daemons, plus more models for Space Marines, Eldar, Daemons, 100+ old metal Harlequins, a mostly unpainted Necrons army, etc.
A fully painted Song of Ice and Fire Starks army, and a partially-painted Lannisters army (a hundred or so more models there).
A couple of dozen painted Cryx models for Warmachine, plus a few unpainted.
Dozens of old Ral Partha and Grenadier D&D minis from my adolescence, as well as Battletech 'mechs in both metal and plastic.
Several full Blood Bowl teams in metal and plastic.
Hundreds of Reaper minis; a small percentage in metal (mostly PCs from campaigns over the past twenty or so years), but a lot more from the Bones 1 and 5 Kickstarters.
Plus some other miscellaneous stuff like a 15mm starter Wood Elf army from Mighty Armies, or all the figs that came with games like Massive Darkness, Advanced HeroQuest, Dark Future, and the new HeroQuest remake, which I backed at the Mythic level and so came with around 75 models.
One of the sad things about switching to online D&D during the pandemic has been no longer being able to raid my miniatures for game play, or rummage through the collection to inspire an encounter. I've had some good ones inspired by a favorite mini or set thereof.