That's essentially Starlink, though for other reasons. But lower orbits see much less of the earth. Earth has a radius of about 6000km, at a low-earth orbit of around 600km you are way too close to have a good view, so you need a lot of satellites to cover the globe. There are also useful special orbits like geostationary orbits (where the satellite is always in the same spot relative to earth's surface) or sun-synchronous orbit (the shadows always look the same because you are in the same spot relative to the sun) that are much higher up.
However with cheaper satellites, cleaning up dead satellites or larger chunks of debris also becomes cheaper, we just need to figure out who has to pay for it. Right now we are kind of stuck with everyone being affected but no one feeling responsible.
International space law, like most other international regulations, is only for the small fries. Any country capable of inserting into geosynchronous orbit with a domestic manufactured launch vehicle is usually also nuclear armed, hold a permanent seat on the Security Council or allied with a holder, and is immune to most low level sanctions. No real space power can be truly bound by treaty if things heat up because they are usually the enforcers.
Also with the cost of sending a satellite to space about to potentially plummet (starship?), wouldn’t it just make sense to make a lot of cheap satellites that you throw up in a low enough orbit that a collision would only require a few years til the shattered pieces de orbit and burn up? We may be on the cusp of a revolution on satellite technology as the engineering work going into each individual satellite drops precipitously and the turnaround time becomes weeks not years. I could see a similar Cambrian explosion in satellite tech from cheap space access similar to when we went from mainframes to pcs. Thoughts?