My understanding is that all new satellites have plans for deorbiting when they reach the end of their lifespan.

That's the plan - but when you have thousands or tens of thousands of satellites malfunctions can happen. Also, lots of existing space debris orbiting the earth that can hit satellites

These low orbits aren't stable though, I think they only have a lifetime of 10-20 years before their lateral velocity decays and they de-orbit on their own, it's not like will just be stuck up there.

No, with orbit altitudes of 1,110km to 1,325km we're talking about many hundreds of years: https://www.nasa.gov/news/debris_faq.html - "Debris left in orbits below 370 miles (600 km) normally fall back to Earth within several years. At altitudes of 500 miles (800 km), the time for orbital decay is often measured in decades. Above 620 miles (1,000 km), orbital debris normally will continue circling Earth for a century or more. "

Ah, I was under the impression that to achieve 25ms latency you would need something very low but it seems to be almost anywhere in LEO would give you close to those speeds.

I was thinking of older speculative articles where HN discussions seemed to think they would only be 300-500 kilometers up, this article states otherwise.

Well seeing as any future business in either rockets or satellite internet both depend on not creating space junk, I think they are pretty motivated to not let that happen.

Humanity is not so good at doing things in their best interests. We have over utilized any natural resource we have ever consumed often to our own determent.

Exactly. Evolution has not primed us with reward mechanisms linked to long term goals relating to pollution or over-utilisation of natural resources. Also financial incentives are often misaligned with these long term goals. As a result we have a tendency to create a mess - on land, in the oceans, in space, wherever we spread

1,110km to 1,325km is actually a fairly high orbit. Estimated lifetime is 1000 years.