I still unironically want a singular variant to rise in popularity, don't particularly care what. There are so many times when "they" comes up and I have no clue if we're talking about a person or a group. There's already enough pronoun ambiguity when talking about single subjects without intoducing a dimension of plurality ambiguity.

If you think that's bad, you should see how ambiguous the plurality of the gender-neutral 2nd person pronoun is!

In some geographic areas, we have "you", "y'all" and "all y'all" which correspond to "tú", "vosotros", and "todos vosotros".

New Zealand (maybe Australia too?) has a solution for that in informal speech: yous!

We have one, but most people probably shouldn't use it.

Many folks I know use "they". Works well enough, I think.

Shall we write "they is pretty" or shall we wonder how many people we are talking about?

We shall wonder about the how many people. This is called the "singular they" and it has been a feature of English for hundreds of years.

https://en.wikipedia.org/wiki/Singular_they

Yes, I'm sure almost everyone reading this was already aware. This doesn't mean that "they are pretty. they are clever. they are ugly. they are good." is a good localization of "ő csinos. ő okos. ő csúnya. ő jó."