Ideas

Very often a language is just a language and you don't want different domain URLs just because the language differs. The current setup is 1 language per channel and therefor 1 language per domain URL.

The possibility to add a prefix to the domain URL is great for some scenarios but not enough for the most common scenario:

In most countries today we speak more than one language
Let's say I create a channel for Switzerland and choose the language Germain with culture Germany.
I need to show this channel also in French, Italian and Romanish and in this case one would want to show the exact same website, structure, assortment, check out setup, domain URL etc. but in different languages.
With the current setup one is forced to create 1 channel per language which results in having different domain URLs just because the language differs.
The example refers to a country with 4 official languages which isn't that common but most countries today have a population that speaks different languages.

A solution to above would also be beneficial for channels who just want to display everything with the exact same setup but in different languages.
There are obviously more scenarios with that same need but not as common as the one above maybe.

Another possible solution to above could be a language selector per channel

If we take the Switzerland example above, the scenario could be something like this:

1. Create a channel for Switzerland and choose German with culture Germany.

2. Add the language Italian with culture Switzerland to enable having our own Swiss content in Italian. (Italian with culture Italy is already used on the Italian channel and we don't want to have their content on the Swiss channel)

3. Activate language selector for Swiss channel and point out the alternative languages you want to show your channel in.

4. A setting for selecting if showing the selector in the header or in the footer on the website.