Thanks for starting off with an insult, when it's your reading comprehension and subject knowledge that's at issue. I'll elaborate for you:

The future will undoubtedly continue toward increasing scarcity of resources among the majority of the world's population. The uber rich will hoard wealth and power, as automation drives down wage growth and job opportunities for large swathes of humanity, even in the developed world.

Zero nations have a game plan for what to do with their economy, as AI and robotics take every job from surgery to coding and repairing themselves. This will lead to increased civil and economic unrest, necessitating increased authoritarianism, as those in power decline to relinquish it, without being forced.

Simultaneously, climate change and technological advancements will increase conflict over finite sources of potable water, arable land, dwelling space within human temperature limits, rare earth metals, etc. The collapse of the oceanic food web due to rising temperature, acidification, and disruption of gyre currents like the Gulf Stream due to lowered ocean salinity, will destroy a significant portion of humanity's sustenance.

All of these effects will lead to increased exploitation of workers, especially minorities and immigrants, as societies become more insular in the face of dwindling access to habitable space, wealth, water, education, etc. This means an increase in terrorism, wars, corporate espionage, ethnic conflicts, revolutions, etc. Now couple everything I've just said with the typical issues of corruption in municipal development, engineering mistakes, human hubris (such as building "The Line" or "The World" archipelago), etc.

That paints a very unsafe picture for human existence. Placing humans in floating cities, which could be shore anchored or deep sea, invites all of the above calamities to impact that city, to an extent much greater than land bound or especially land locked cities. Floating cities are likely to be good candidates for bases of petroleum extraction, desalination, and aquaponic food production. That paints a giant target on that city when it comes to human conflict.

The hypothetical possibility of destroying a floating city utterly is far greater than for a traditional land based city. Making floating cities then prime targets for terrorism and first strikes by nuclear or conventional forces, not to mention pirates and insurgents. Additionally floating cities would be far easier for attacking forces to reach (you can't drive a boat to attack Denver).

Coastal cities have always been more vulnerable to attack for all of recorded history. This flaw would expand with floating cities, as they could be attacked from literally 720 degrees. Depending on the location of the city, it would be as vulnerable (likely more so) to damage from natural disasters, like the ones I mentioned in previous comment, as traditional coastal cities. A near shore city is highly vulnerable to typhoons (or hurricanes) which cover the majority of the world's oceans, in the prime human habitable latitudes. Even deep sea cities would be at risk from super storms, that will become increasingly common.

They are also more vulnerable to tsunami, as they couldn't be anchored in bedrock to the same extent a traditional city could. They would fare even worse than the cities we've built on dredged "reclaimed" shorelines. Likewise they are vulnerable to rogue waves, should they be open water or shore impacting. You need to learn more about rogue waves if you think they only occur on open ocean. One sank the Edmund Fitzgerald on a Great Lake, for example, and rogue waves can absolutely hit shorelines.

All of the climate and human based calamities I listed will be exacerbated by the factors I mentioned. On top of that, add the terrible job maintaining municipal infrastructure we already do as a species, which would be even worse when moved to a maritime environment. Now, maybe you understand why I said I would not live on a floating city. Or, perhaps you'd like to insult me again. Luckily, I do not care, either way, and am done with this conversation. Good bye.