Performance-wise, a lot of cars these days are "sporty". They accelerate, brake, and handle better than supercars of the 80s.
While true, this is also sorta cherry-picking. When I was a kid I was a HUGE fan of Corvettes so I know some of the information for them, I'll use them for an example. Base-Maximum available Corvette HP:
- 1966: 300-425 (427)
- 1967: 300-435 (427 with a six pack)
- 1968: 300-560 (427 with 12.5:1 pistons and an ENORMOUS 850cfm Holley four-barrel)
- 1969: 300-435 (but this was HIGHLY conservative 427 with 850cfm Holley four-barrel)
- 1970: 300-465 (454 with 800cfm Holley four-barrel)
- 1971: 270-425 (454)
- 1972: 200-270 (454)
- 1973: 180-275 (454)
- 1974: 195-270 (454)
- 1975: 165-205 (350 until otherwise noted)
- 1976: 180-210
- 1977: 180-210
- 1978: 175-220
- 1979: 195-225
- 1980: 180-230
- 1981: 190
- 1982: 180-230
- 1983: N/A, Due to introduction of the C4 (1984-1996) and a labor issue there were no 1983 Corvettes they ran the 1982's late and started the 1984's early.
- 1984: 205
- 1985: 230
- 1986: 230
- 1987: 240
- 1988: 240-382 (Callaway Twin-Turbo)
- 1989: 240-382 (Callaway Twin-Turbo)
- 1990: 240-375 (ZR1)
Horsepower just plummeted with the implementation of EPA mandated Pollution Controls and CAFE standards in the early 1970's and it took about two decades to recover. From 1966 (at least, I didn't look farther back) until 1970 you couldn't get a Corvette with less than 300 HP and starting in 1972 you couldn't get one with more than 300 HP until the introduction of the Callaway Twin-Turbo and then the DOHC ZR1 almost 20 years later in 1988 and 1990 respectively.
For the Corvette power bottomed out in 1975 when the base model had an anemic 165 HP and even the high performance optioned cars only made barely over 200 HP. You can buy a minivan today with power in that range.
Note that this was not just a Corvette, just a Chevrolet, or even just a US Automaker issue. When the 382 HP Callaway Twin-turbo Corvette was tested by Car and Driver in 1989 they stated that the "staggering" 382 HP was "more power than any U.S. spec model currently sold by Ferrari or Porsche. In fact, we know of only one U.S. market car that can top the Callaway's formidable power rating: the Lamborghini Countach, which belts out 425 hp."
So as of 1989 the two most powerful cars available in America put out 425 and 382 HP and they were incredibly expensive. The Callaway Twin-Turbo was a $26k option on a car with a base price of ~$31k. Ie it roughly doubled the price of the car. Meanwhile the Countach was about three-times as expensive as the Callaway Twin-Turbo 'Vette at $145k. For comparison in 1968 a base Corvette was $4,320 (convertible) or $4,663 (coupe) and you could get a 400+HP big-block for as little as just over $300.