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.

Note that the data for the first graph you mention is heavily smoothed: "Because of the limitations of data sampling, each curve in the main plot was smoothed (see methods below) and consequently, this figure can not resolve temperature fluctuations faster than approximately 300 years." That means it shows slow fluctuations, but can never show rapid changes like the rapid increase in temperature we're seeing now (but note that the 2016 temperature is marked there with the arrow labeled "2016"). The other graph, the one that starts 2000 years ago, does show the recent rapid increase.

> If you remove dotted predictions from your comic it suggests the temperature increase in the last 2000 years is about 0.3 - 0.4 Celsius degrees

I don't see where you get the 0.3 - 0.4 from. Looking at the last 2000 years on the XKCD graph, the temperature in year 16 is a bit under the reference, and the temperature in year 2016 is about 0.8 degrees above the reference. That's easily double your 0.3 - 0.4.

> This is pretty stable and is not matching past fluctuations, which are more accurately depicted here

I don't understand how you come to that conclusion. Both the XKCD graph and the graph you mention (the Wikimedia graph covering years 0 - 2016) show that 2016 temperatures are clearly higher than anything else we've seen the last 2000 years. Also note the arrow marked "2016" on the long-time Wikimedia graph indiciating the 2016 temperature, much higher than any other datapoint on the graph. The graphs simply don't support your conclusion.

> Another thing is that we're assuming that the current climate conditions on earth are becoming less optimal, which is unsupported. The current climate might actually be better. There are many examples, both negative but also positive, of the climate change.

There is scientific evidence for more severe tropical storms, rising sea levels (causing severe problems for the large fraction of the world's population living close to the sea), droughts, more severe weather (we're already seeing problematically hot heat waves). What are the positive effects that offset those negative ones?