> This lead to decades of low quality cars being made.

Really, it was only a bit over one decade. Taking GM as an example, their last great cars were produced for the 1973 model year, after which point the economy, emissions, and efficiency requirements resulted in drastic (bad) changes. It only took until the late 1980s for them to make some genuinely good vehicles though. For instance, the Buick Regal/Oldsmobile Cutlass/Pontiac Grand Prix from 1988 were well built, comfortable, handled (relatively) well, and were very reliable - especially from 1990 with the introduction of the 3.8L V6, what is likely GM’s most reliable engine ever built (second possibly only to the small block V8). The same was tru for their sports cars (while not making much power out of the displacement, the TPI V8 firebird and corvette were similarly efficient to European sports cars at the time). Many GM cars from that era (late 1980s until early 2000s) are some of the most reliable American cars ever built.

The same is true for Ford; for example, the 1988 Probe, while not the most popular vehicle, was very reliable, comfortable, efficient, and well-built, likely in part due to their partnership with Mazda. It could reasonably be argued that as early as 1980, Ford was making pretty good vehicles, with the Mercury Grand Marquis/LTD Crown Victoria being well-built and reliable, if very down on power with questionable efficiency.

Not worth talking about Chrysler because they didn’t know how to make good/reliable cars before the fuel crisis and they certainly didn’t figure out how to afterwards.

I know this isn’t your main point but it’s worth considering that the US did actually figure out how to build really good cars again, and it didn’t take them that long. Mid-90s to early-00s American cars were, in my opinion, at the perfect point of technological advancement: CAD and high-precision/low-tolerance manufacturing resulting in engines that last well over 300k miles without major servicing; enough computer advancement to have high precision per-cylinder fuel and spark control with accurate air metering leading to better power, efficiency, and reliability; and enough material advancement to have interior and exterior build quality that makes the car look like it wasn’t built in a shed. But most importantly, they hadn’t figured out how or where to cheap out on components, so you end up with the “unreliable” components (like the 4L60e and 4T60e transmissions) “only” lasting 200k miles before requiring a rebuild - which in today’s money is still less than $1000, let alone 20-30 years ago.

From the birth of the US auto industry until about 2010, the only period where there wasn’t a single American car worth buying brand new was probably 1974-1981. The “malaise era” itself was by the loosest definitions only about 13 years, from 1974-1987.