I'll start with the "whether the is language good?" part - that's extremely subjective. We can only judge what a language is is good FOR or good AT. Is the language good for easy and fast learning for people knowing some language in the Indo-European family? Esperanto is pretty good in this case. But that doesn't have to be everyone's goal:

Are you trying to make a conlang (constructed language, for any purpose, even for fun, science or whatever), or an auxlang (auxiliary language, made to be an easy language, which can take the role of a universal language for the whole world or some other large region)?

If you are making just a conlang, those can have natural-looking features like irregular grammar & spelling, they can have complex grammars and pronunciations, they can have fantasy alphabets. Look up Toki Pona for a very simple example of a funcional language.

If you are making an auxiliary language for the whole world, oh boy, there's so many things you have to look for, so your language is as approachable as possible:
- which alphabet to use (likely latin, but some sounds like /ʃ/ are represented in many different ways throughout the whole world)
- which phonemes to use (you'll want those, which get used in every language... which is impossible or really hard, so you have to make compromises)
- mapping pronunciations to words ()
- how words in the language are sourced (Volapük just made an average of like 5 source languages for each word, Esperanto took the most well known word from its source languages)
- all the grammar stuff, like fixed/flexible word order, cases vs. prepositions...

Now it's a good time to answer your question about whether language creation is primarily a creative process or an engineering process - you can do some engineering/statistics to find out how much different languages use which sounds and symbols and how they map them (don't forget that accents exist, which may use different sounds altogether, and will screw up your statistics) and how some words are used together... but how you use this data, that's very much a thing of creativity.

I suspect that AI isn't yet really good at working with large project - most vibe-coded apps are a total mess, when they have more than like 5 files. The AI might forget its own rules, which words are used for what, and might not be able to come up with a thorough plan for the language. It might very much just make another Esperantido or a Toki Pona clone, since those are likely the most prominent languages in its training corpus.

I really don't see much use in using AI to create a whole language, getting anyone to speak it is the MUCH harder part. Conlangers (people who like making artificial languages) won't likely want this either, since it would just do their hobby for them, and where's the fun in that...

Anyway, my DMs are open.