Mkv ain't even out yet and its already slower then the competition
What are you classing as competition?
The new Supra does 4.3sec to 62mph/100km/h (so a bit less to 60mph) and an electronically limited 155mph, for $50k.
A Mustang GT is cheaper (~$35k) but no quicker (also 4.3sec to 62mph with the equivalent auto, slower with a manual) and matches its top speed. A GT350 is marginally quicker than the Supra but $10k more expensive. A Camaro 1SS is also cheaper (~$38k) and has similar acceleration (4.1sec to 60mph - so probably similar to 62mph) and once again does 155mph. Again, you can get a faster Camaro, the ZL1, but like the Mustang that's also significantly more expensive ($12.5k more than the Supra). More or less the same deal with a Challenger: R/T is cheaper (~$34k) but slower (4.4sec to 60mph). Top speed is very difficult to find for some reason (I've had this problem before with American stuff) but I'd be surprised if it's significantly different. A Hellcat, obviously quicker, is once again more expensive (by $10k+)
So the Americans field cars which are cheaper for similar performance or quicker for significantly more expense. Whether you consider them competition depends I suppose on whether 0-60 times are literally the only metric you measure a car by, but I'd not personally class a four-seat 3705lb Mustang, 3760lb Camaro or 4162lb Challenger as rivals for a two-seat 3300lb Supra.
Asian brands? $50,790 gets you a Lexus RC 350 F Sport (5.8sec to 60mph, 143mph, 3748lb). Nissan gets you a 370Z Nismo (4.9sec, 155mph, 3520lb) for $45,690. I can't see what Infiniti's closest product is because Nissan and Infiniti's US sites are somehow blocked for me, but I suspect nothing overly different from the equivalent Lexus. Honda and Mitsubishi, I assume, have nothing comparable. Hyundai no longer sells a Genesis coupe. I like the Kia Stinger, but nobody is gonna be cross-shopping that with a Supra, so that's out too.
So the Japanese and Koreans can't really be considered competition either - the two best offerings are either similarly priced and slower (Lexus) or marginally cheaper and slower (Nissan, which is also as old as time itself). You can get a faster Lexus RC obviously (or an LC), but that's a) more expensive and b) it's literally another Toyota anyway so not really competition.
So now the Europeans. Closest Merc C-class Coupe is a C43. Great car - but more expensive (~$56k) and slower (4.6sec). Audi? S5 Coupe. More expensive (but only just, at $52,400) and slower (0-60mph 4.4sec). Both are also larger and heavier (3968lb and 3860lb respectively), both are all-wheel drive, and neither is really a sports car. The obvious one: BMW. M240i has the same engine as the Supra. It's cheaper - $45,800 - but slower (4.4sec) and heavier (3439lb). The new Z4 then! It's literally the same car, if the internet is to be believed. More or less the same price too ($49,700). But... err, it's slower (5.2sec) and also has no roof, which may not interest everyone.
Want to get weird? The Alfa 4C. Proper two-seat sports car like the Supra. But oh, it's $66k, now Spider-only, and only marginally quicker at 4.1sec to 60mph. Plus if people are complaining about the Supra being too small they ain't gonna want to live with a 4C. Alpine A110? For me personally it's the car I'd likely choose over a Supra - mid-engined, great styling, similar price, great brand heritage. But (sad trombone) it's not available in the US. And like most of the others here, it's slower.
Now I'm not familiar with every car in every market so I'm no doubt missing something (possibly even something obvious) but I feel like I've covered pretty much every base here. Very few of the Supra's "competition" is quicker than it, and while some (the Americans mainly) are cheaper and give you more cylinders, they're also large, heavy and unlikely to be a dynamic match for the Supra in anything other than lateral grip (which admittedly people seem obsessed by but then if you're obsessed by 0-60 numbers then I guess skidpad figures matter too).
Oh, and an A80? $45k in 1994 for the Turbo (so $76k in 2019 money), 0-60mph in 4.9sec, and 155mph. So... more expensive and slower.
So again... what competition are you actually referring to?