I think the entire tech that I worked on has been superseded by better technologies. However, I (think?) the limitations are still of interest because they influenced the original sequencing and probably a lot of the early data.

The other takeaway I had, as someone who came to this with a CS and stats background, is that chemistry sucks. None of it is deterministic, and when people say some chemistry does X, what they really mean is it generally does that. Most of the time. Subject to conditions and a reasonable amount of stochasticity. We're built on a pile of random muck hacked together.

Older tech stays around quite a while! No sequencing technology is perfect, so even Sanger sequencing is still used quite a bit for various tasks from clinical sequencing to validation studies to anywhere you just want to phase something that's longer than 300bp, etc.

And yes, the chemistry that biology takes advantage of means embracing uncertainty in the world. It's all thermodynamic chances, with lots of non-linearity added on top of it all.

Sanger sequencing is still about 1/3rd of the market by dollar value. There is more Sanger sequencing being done today than 10 years ago.