I wonder what the market is like. I'm vaguely aware of Warhammer as a hobby, that's adjacent enough to my social media that I can "see" it, but not people buying miniatures. Does it sit adjacent to railway modelling? Are people making dioramas of Waterloo still?
.. a quick check reveals that OO is 1:76, so they wouldn't quite be right.
Anecdotally, wargamers do not use those minis much. Some older gamers started out with playing more or less improvised wargames using 1:72 (mainly Airfix) figures in the 1960's or so, or playing games like Fewtherstone's wargames perhaps, but it is rare to see them now. Historical minis as a whole are less common now, but those that still play either use metal figures or figures from more wargame-specific companies (usually using more common game scales like 10mm, 15mm, or 28mm).
Most 1:72 ranges seen on that site (that I spent many hours on) are not that great for gaming. Lots of useless poses that are more for dioramas (or as kids toys maybe?). For gaming you need more just simple infantry walking or firing in some kind of good combat pose, but you often only get a handful of those in a set of 40+ figures, so it does not become very cost effective. Many poses look good, but not what you probably want to build armies for a tabletop.
The US preferred 1:87 historically. English 1:76 and American 1:87 trains run on the same size track, but the English models are typically built slightly over-size because their smaller bodies wouldn't fit a good motor easily.
If you want to this historic wargaming hobby in action: https://www.youtube.com/@LittleWarsTV
Of course the chart is bunk. It represents variety, not volume.