In a market where companies are pushing the edge of what magnification ranges we're able to useably accomplish, they aren't doing so without sacrifice. Every popular company seems to be experimenting with 10X and 8X erectors, thus making sacrifices at one or both ends of that range.
By this point our technology has close to mastered 3X and even 4X erectors [and especially fixed power optics]. It's cheaper and easier than ever to create a 3-9 scope or 4-12 scope with excellent eye box, FOV, DOF, etc,..
So why is nobody making a bombshell lower "range" variable optic today with great specs and features for less than your current 10X and 8X wonder scopes? Surely there's a market out there for people who value comfortable usability over extreme mag ranges.
[Edit/added:]
Just about the only scopes that are still using shorter erector range technology seem to be doing so because they're made in cheap Chinese OEMs that can't do more at that price point.
A notable exception which I'm aware of is the Swaro Z3 line which gives excellent glass, resolution, eye box, etc,.. for the sub-$1k price point. It's only lacking in reticle options and durable construction, which can both be improved while keeping the benefits of the short erector.
With any of these situations "follow the money" applies and this sometimes flies in the face of reason, be it military contracts or perceived civilian interest. A great example of this would be the success of the NF ATACR 7-35 in PRS style competition sports. We could debate until the cows come home as to whether it is the upper magnification range this scope offers or other features (like that fact that the majority of owners say it has better glass than the ATACR 5-25 which struggled to gain nearly as much popularity). Regardless of what "exactly" was the reason for the 7-35's success, many other companies began duplicating this design whether it be a 6-36, an 8-40 or even TT's new 7-35 design. For most, anything above 25x really doesn't matter outside of LD work, you're certainly not going to shoot a PRS competition at 35x (and if you do you will likely struggle) because FOV wins the day when trying to find multiple targets hidden in the field. I see more application for the "above 25x" magnification scopes in the rimfire competition where shorter distances and higher magnifications could actually help in certain situations.
All that being said, I agree there is merit to your thought on making a superb 3x/4x scope using today's technologies while keeping the price down but quality up. Kahles had their amazing 3-12x50, NF has their ATACR 4-16x42 and so forth but sadly these scopes appear to be a dying breed, why should a mfr invest in a 3-12 or 4-16 when everyone appears to want a 3-18 that can cover both? Will the 3-18 be as light, not likely, will it be as short - probably not and if it is, a short scope with high erector tends to have issues with eyebox, parallax and DOF (aha, now we're onto something), but how many are willing to sacrifice these things to "get the range" or how many ignore or don't even know what they are missing. This reminds me a little bit of the camera world when the 28-200 f/4.5-5.6 lenses were all the rage, why would you buy a 28-70 when you could have a 28-200? Well, for one simple reason - image quality, so while the consumer market pursued more and more magnification (they now have 24-200 and 28-300mm lenses) the professionals knew to stick with the tried and true 3x magnified f/2.8 zooms because they offer the best performance.
Schmidt changed the landscape of the long range scope back in 2005 with the release of the PMII 5-25x56, if memory serves this was the first alpha class scope to offer a 5x erector, but maybe even more so - PRS changed the landscape and demand for high quality long range FFP optics, without PRS I doubt we'd have as much innovation as we have today (the military certainly wasn't going to do it, though they do play their part) because people are willing to spend money on things they perceive will give them an edge and American's are really good at this (though COVID and Bidenflation are doing their best to put a serious damper on the ability for American's to spend money on non-essentials), so putting a Chinese mfr'd virus and Brandon aside for the time being, what drives a manufacturer to invest R&D dollars is their perceived ROI and right now the risks don't outweigh the reward even if we (the shooting community) say we'd love to see a high end 3x/4x scope that is priced decently. George at GA Precision was able to convince Bushnell to continue to make the LRHS 4.5-18x44 even though Bushnell had abandoned it, and while these scopes are loved by many, I'm sure Bushnell saw a falloff in sales as other companies came out with 3.5-18 and 3-18 designs and so forth. That being said, Leupold did come out with their Mark 3HD line of scopes, not sure how popular they are but that is one example of a big mfr testing the waters of somewhat more high end 3x scopes.
