system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are "verbs of being" irregular in so many languages?

In my own studies of Latin, French, and Swedish and limited forays into German and Spanish, I have not come across any languages with a verb of being that had a regular pattern or conjugation. 

EX: 
English: (To be) I am, you are, (s)he is, etc. I was, I shall, I will...
Swedish:(att vara)  Jag ar, du ar, hon ar... 
Latin: (Sum, esse, fui, futurus)  Sum, es, est, sumis, estis, sunt....
French: (Etre) Je suis, tu es, il est... Je serai.... 

I suppose the short answer is that languages are linked (Latin to Romance languages, etc.) but why does such a pattern perpetuate? What are some languages without that? Is this linked to other language trends?
gpt
Words that are used frequently tend to be more grammatically irregular in most languages. "To be", "to have", and "to go" are all very common words and are irregular in a lot of languages.

Languages often change by either contraction or analogy. In contraction, speakers end up saying things with different accents or speak quickly and the form of the word changes that way. With analogy, speakers copy the forms of other words (e.g., you may not know what an "estuary" is, but you know that the plural would be "estuaries" by analogy). Contraction tends to lead to irregularity and analogy to regularity. Contraction is also more common with regular words because they are spoken more frequently and as a result there is more chance for contraction and people will recognize them even when contracted. The end result is commonly used words tend to morph more often and become irregular while more uncommon words tend to stay regular.