Then where is the problem? If the support can read Polish they will pronounce your name properly, if they're from India they will mess it up, why should we have different expectations? Nobody will identify you by name anyway, they will ask how to call you (chatbots do this already) and then use for proper identification all kind of ids and pins and whatnot. So we are talking here about a complexity that nobody actually needs, not even you. So let the name be saved and displayed in the nice native way, and you as programmer make sure you don't go Bobby Tables with the strings.

>if they're from India they will mess it up

Or not able to read at all.

>Then where is the problem?

Since you don't indicate for what purpose my name is stored, which may actually be display only, any of the following can happen:

A name as entered in your system is compared to a name entered in a different system or when you interface (maybe indirectly and unknowingly) with a system using different constrains or a different script, maybe imposed by their jurisdiction. As a result, the intended operation does not come through.

This may happen in the indirect way and invisible to you -- e.g. you produce an artifact, say and invoice or issue a payment card using $script a, which I will only later figure out I can't use, because it's expected to be in $script b, or even worse be in $script a presumed to match $script b they have on record. One of the non-obvious ways it can fail, is when you try to determine whether two names in the same script are actually the same to infer family relationship or something other that you should not do anyway.

It may happen within your system in a way your CSR will deny is possible as well.

That's on a more severe side, which means I will not try to use the name in any rendering that doesn't match MRZ of my identity document. Which was probably the opposite of what you intended allowing arbitrary bag of bytes to be entered. No, that is not made up problem, because I'm bored, it's a thing.

On a less sever side, not understanding names is a failure in i18n department, because you can't support my language properly without understanding how my name should be changed when you address me, when you simply show it near user icon and when you describe relations between me and objects and people. If you can't do proper i18n and a different provider can, you may lose me as a customer, because your attitude is presumed to be "everyone can just use ASCII and English". Yes, people exist that actually get it right because they put an effort in this human aspect.

On a mildly annoying, but inconsequential side people also have a habit of trying to infer gender based on names despite having gender clearly marked in their system.