In my native Czech we use plural when addressing strangers or people with a higher standing. Singular pronouns are a lot more informal, used betwen friends and family. French and German have something similar.

Actually, English does the same, except the uncouth singular has been dropped and now the formal address is the only choice. The informal, singular version of "you" is "thou".

You can read more about it here

Spanish is one. Western Hemisphere Spanish has different second-person singular pronouns depending on relative status / formality / familiarity. One uses "tu" for inferiors, intimates, and children, and "usted" for superiors and respected strangers. Spain does as well, but they also have variants for second person plural pronouns.

Japanese for example. Pronouns like he (kare 彼) or she (kanojo 彼女) aren't used as frequently as in English or many other western languages. Usually it is familyname + status-suffix.

For example: Smith-San(さん) -> Mr/Mrs Smith

Tanaka-Sama(様) -> Very respectful form of adress

Aoyama-Sensei(先生) -> Teacher/Doctor/Artist

To any native/professional speaker: correct me if I'm wrong.

Japanese does this, and doesn't half-ass it either! https://en.wikipedia.org/wiki/Pronouns_in_Japanese#List_of_Japanese_personal_pronouns

Hell, Japanese essentially has entire modes of speaking just to be polite, with whole sets of pronouns, verbs and speaking style. https://en.wikipedia.org/wiki/Honorific_speech_in_Japanese

Incidentally, from a Euro perspective, tons of "our" languages, and formerly English (thou/thee) have what is called a t-v distinction, named after Latin "you" (tu/vi) which depends on status much like "usted" in Spanish. There's a list of languages which do this.

Vietnamese uses both status and gender. For example, there are different terms associated with older brother (anh) or sister (chi) vs younger siblings (em). You generally wouldn't use any of those terms to address someone older than your generation, as there are more respectful pronouns you would use.

Excuse me, is this sir's suitcase? Can I help sir with this?

Replace with ma'am, master, etc

In many languages the plural form is used similarly. In my native danish it's "De" vs "du" (De is always written with a capital letter)