So what you're saying is there's no reason to have a GS in the first place and/or that it's a very niche car. Which we knew - BMW has essentially the same problem with the 5 Series.
If you think about about it historically, there was - at one point - a very clear case for an ES and GS. The ES was a smaller, entry level product that competed more directly with the C Class, while the GS was a true midsize sports sedan that was more aimed at the E Class and 5 Series.
Over three generations, Lexus grew the ES to now being the second-largest sedan in the lineup, while simultaneously neglecting the GS by eliminating it's performance credentials for the 3rd generation and then dropping the V8 for the fourth generation. So what you end up with is two cars that aside from their drivetrain layouts are now very similar, with one having a massive price advantage over the other. Furthermore, FWD vs RWD doesn't really matter much to every day consumers - people come in wanting a "midsize Lexus sedan," and the ES ticks most of those boxes while costing significantly less.
This issue has been compounded by Lexus dealers who know the ES is a quick sale and who don't put the effort into socializing the GS with consumers. I worked in a Lexus dealer for 3 years and saw this happen numerous times: Someone could come into the dealership with a GS wanting another one, and sales would automatically usher that person into an ES because it's what they had on the lot. I saw people come in with E Class, 5 Series, etc. saying, "I want to look at a GS," and the dealer would generally say, "No, no - have you seen the ES?! The ES is what you really want!" Dealers have decided they already know what consumers want, and quite frankly, history proves they're probably right.
Depending on size, a dealer's inventory generally looks something like:
5-7 black on black ESs
5-7 white on tan ESs
2-3 Silver on black ESs
2-3 extraneous color combinations of ES (Burgundy, blue, champagne)
1 black GS F Sport
1 white/silver GS base
... and that's about it.
Dealers stock what they know they can sell quickly, and that's ES in popular color combinations. At the same time, Lexus has given them that car in the ES, which is bigger than the 5 Series and E Class but costs half as much, so consumers feel like they're getting a great deal on a "Lexus midsize sedan," and some of them don't ever even get to see or consider a GS.
Looking forward at some of the rumors and speculation, if it plays out as planned, what Lexus is about to do is brilliant. If they elevate the ES slightly and offer an F Sport variant along with optional AWD, they'll probably capture 70% of the people who would have bought a GS while only offering one vehicle in this segment. Think about ES with FWD, AWD, 4cylinder, 4 cylinder hybrid, V6, F Sport, luxury package, etc. Even if they bump up the base price to $40-42k, they have already undercut the E Class and 5 Series by $10k and those are base models. You'll probably be able to snag a really nicely equipped ES for $46-48k, and that'll be something like $20k less than a comparably equipped E Class or 5 Series. Lexus is about to do to Mercedes and BMW what they already did to the GS, and they can do it because they have the scale and flexibility with TNGA-K to price the car so low. In addition, they already know people don't care much about FWD vs RWD, and those few who do are already going somewhere else anyway. Plus consider the mass exodus from passenger cars to light trucks - they are positioning the ES to run cleanup on the entire segment.
On the flip side, if you elevate the GS to being an ultra dramatic 4 door coupe, you have the ability to pick up that midsize sedan buyer who DOES want the performance and drama an ES won't offer, while being able to compete against the E Class and 5 Series at the top end, not to mention A7, CLS, and 6 Series GC. They can also offer GS F and not have to bother with ES F, leaving the ES to completely fill that "every day luxury sedan" space. It also gives Lexus an emotional car that's more attainable than the LC, and hedges their losses in the ES/5 Series/E Class segment as sales there drop off but sales of 4 door coupes remain strong. Also consider the rumor of "GS Sport Cross" - this gives Lexus something that's sportier than RX and NX, and it's a size in between them. This would also be a great playground for Lexus to experiment with BEVs, plug in tech, etc. A product that's more niche and more emotional will be better received with such tech, I think.
I think the last decade for GS and ES has been very transitional (hell, for Lexus as a whole), but I really believe what they're about to do is very smart. We'll know soon.
