I think the problem is that when you call yourself "they", it sounds like you are talking about several people. So how are people supposed to know what you are talking about. I'ts impossible to know what you mean. Your friend might understand, just be aware that the world will not understand what you are talking about if you do that.
I take your point, but English already contains so many ambiguities like that, which need to be figured out according to the context. Like
you in English can be singular or plural, so you don't know, when someone says
you, whether they mean one person or multiple people, and when you're writing you sometimes have to go out of your way to make it unambiguous by using another term (name/s) or supplementary information to show which one you mean.
(And I could have written the above sentence as, "Like
you in English can be singular or plural, so one doesn't know, when someone says
you, whether they mean one person or multiple people, and when one is writing one sometimes has to go out of one's way to make it unambiguous by using another term (name/s) or supplementary information to show which one one means." ...but I think that sounds more confusing, less friendly, and a bit snooty than how I've said it, by using "you" like "one unspecified person." At the end of the day I think we use language to express those individual preferences, as well, and it shows people something about who we are and what's important to us.)
As a teenager getting used to English, I spontaneously adopted
they instead of
him/her or
he/she when writing general sentences about people, because I found putting it as
him/her or
he/she more awkward, and didn't like the custom at the time of referring to unspecified people as
he, because it left out a whole gender - like the old terms chairman, charwoman etc, which also were used to transmit gender biases. I needed a neutral pronoun that wasn't loaded with objectification connotations, and this worked for me. I still write like this, "A person may think ABC because they've experienced XYZ."
Oh English - the language where you have to surreptitiously skip ahead when reading out loud when words like
bow are in a sentence, so you can glean from the context if it's talking about a means of shooting arrows, the front bit of a boat, or someone bending to someone else in greeting or respect, and can then choose the correct way to pronounce that word on the hop!
Phonetic languages don't present us with these problems, but English is also a lot of fun, and can be milked for comedy value because of these things - like other languages for their idiosyncrasies, such as the ability to make up any compound noun at wish in German...
I give you the old Donaudampferschiffahrtsgesellschaftskapitänsmützenstern: The star on the hat of a captain of the Danube steamship company - apparently with three fs since 1996, Schifffahrtsgesellschaft etc.
And we can make that word longer still, if anyone wants to.
Language is such fun.