I'm only now after 55 plus years of riding thinking that I might be able to pick a bike that fits me by geometry specs alone. But I doubt I'll ever try. I like the touchy feely part of looking for new bikes.

Your fit on a bike is essentially from saddle to the hands and saddle to pedals. Then a certain amount of bar drop to get you where you want with the angle of your body, but then that plays with how far your hands go out too.

Frame measurements just don't give you that information easily. Frame reach, frame stack, seat tube length.... They leave out the seat post and saddle, some times they don't tell you the crank length. They seldom have the stem length and bar reach and drop.

As well the angle of the seat tube will make some difference for how you perceive the fit as that changes the position of the BB and cranks in relation to where you sit.

So when they tell just find a bike with these x, y and z measurements..... well, good luck. It's not really easy. Essentially to me, it's no better than just using the manufacturer's suggested sizing.