A few comments.

If one is frustrated by how bike manufactures label their geometries then either measure all their bikes yourself and make your own charts or create your own brand and label the geometries the way you think is right. This issue is really one for those who shop without trying. I don't accept the excuse of "at the last shop I had fit me I ended up on a bike I couldn't stand over". Bad fitting session/communication, not bad geometry information. This is why the LBS is the best source for information about how a bike feels. That's the only place you can touch, stand over, ride BEFORE buying. This should be worth a lot, but is discounted frequently because in the interweb age we are all experts...

Manufactures measure their geometries differently because they can, like tire size labels. It makes exactly what the OP is complaining about happen, the on paper info isn't completely transferable between brands. The brands that sell through (the listed Raleigh, Trek, Giant and most others) the LBS chain really want their potential customers to go to their dealers. For better or worse this is the distribution model they have invested in.

Stand over can be measured at the front top point of the top tube. This is a more realistic location for human parts to be located near then the middle of the TT. Remember that the seat takes up some of the TT length then there's one's butt and body before the front equipment is going to touch a TT. Lastly when dismounting it's common to lean slightly forward, further bringing the human parts close the front of the TT. Now not all brands do this measurement this way, just saying some do for a reason.

While stack and reach (the new/current dimensions) do describe a better set of fit aspects they don't speak to the seat/pedal relationship at all. If one has a good grasp on the classic geometry data these two new ones don't add more info. If one doesn't have a good grasp of classic geometry data then these two alone aren't going to insure a good fit.

Not directly mentioned yet (but alluded to indirectly) is BB drop. A large drop (or low height) VS a shallow drop makes a big difference in how "big" the bike fits.

One of the advantages that was trumpeted when the current wave of sloping TT bikes came about (and I say current because any student of bike history knows that sloping TTs have been around for 100+ years and were the standard a century ago) was the increased frame stiffness. Maybe an issue for the taller sized bikes (and I even question the stiffer is better claims) but for the sizes that I ride stiffness isn't the issue. Fitting a second water bottle, or rack, or seat bag is. Andy.