Sorry, here's where you go wrong.

If we continue with "business as usual" we will hit +5ºC warming and go past that.

In that scenario, most of the tropics will start to have long periods of heat that will kill anyone not in air conditioning. We are already seeing the beginnings of this.

Four billion people live in the tropics. How many of them have air conditioning? And how can a country survive if people can't go outside for months in the year?

Now look at drought. California, for example, has for the past several years been in the worst drought in over 100 years. At +5ºC, these droughts will be permanent. And that will mean that a great deal of the world's growing areas, won't.

As for your "50 centimeters of sea level rise" - the last time in geological history CO2 levels were this high, water levels were 15 to 20 meters higher than today - source. And CO2 is by far the strongest driver of water levels.

Over a billion people live within a couple of meters of sea level. All those places will now be 10 meters under water.