It might be better, true (apart from the thermal limit thing in the article, that's a hard limit). But our civilization is set up for the climate of the last few hundreds of years, reflected in our distribution of cities and infrastructure.

If you were to change the sea level either way many cities would either be submerged or far from the sea they were close to since it's useful. If the precipitation patterns change the arable land distribution and ground/runoff water availability will change, the soils and landscapes are not adapted to that yet. Animal and plant behaviour will be different, but in many areas humans are dependent on them. Further out, if any of the atmospheric or ocean circulations change to a different pattern, it will change the local climates as well, with all and more of the above effects. To live in a fast-changing world is hard in itself too, it is unclear what to expect for the near and mid-future, making agricultural and infrastructure planning very hard.

So even if the end-state was preferable, the transition will be very painful, for us and the natural world.