EDIT:
maybe 4 cores are enough for development using non-compiled languages, and if you don't use Chrome and Electron apps, and not running several VMs and docker containers.
Some programming languages like Julia and Erlang/Elixir will happily use all the cores available on your laptop to speed up calculations, run builds, tests and other development tasks.
It all works without hitch and if there is a hitch it is typically Chrome or Gnome misbehaving, not lack of cores.
I get this all the time with my MacBook that I use for development. Run 1 or 2 of them is fine, but 10 or more at the same time and it will run the machine down to the ground.
The advantage is that it allows people to make windows, Mac and Linux apps with ease.
They're not going to go anywhere unless there is a better alternative.
Coding native is a waste of money in most cases. Especially for a chat app.
Hardware manufactures sell computers. The computers they sell need to be able to perform well on the applications that exist today.
There's no point saying the apps are shitty if the laptop they're trying to sell doesn't run well with it.
Maybe today laptops should have 16gb of ram at a minimum.
AMD's resurgence has shown Intel in some cases dropping the price of their CPUs by 50%. Maybe cheaper computers need to be more powerful.
I don't agree with it ideologically because I moved to mac because I loved how Cocoa apps felt, but honestly Microsoft has the right idea in just embracing it because it isn't going anyway any time soon so best just to make sure they run well on your platform.
But saying that 4 cores is ridiculous misses the truth. A lot of people, myself included, use 4 core machines completely successfully.
If you need more, there is absolutely nothing wrong with paying more for more powerful machine. It's just not every PC on the market has to have absolutely most powerful configuration available at the moment.