We must be happier unless Keigo -polite expression- exists

I was wondering people could be happier more than now if Japan did not have Keigo culture when I was working in a restaurant as a part time worker.
I use Keigo, sure. Because I am a clerk and I must welcome guests who came to the restaurant to eat something.
It is our, clerks’ duty.
However, a half of customers do not use Keigo for us.
Some of them treat us like slaves because we are clerk and they think customers, means them, are on a high position than us.
Most awful customers among them are people who look down on us because we are YONGER than them.
When I welcome elder customers, often they order something like little kids.
„Do it!“, „I need this“ or „I am waiting for this dish. Quick“ etc.
These expressions are rude but we need to use Keigo.
„Thank you for ordering, sir“, „I am so sorry. Please wait a second“…
We say them with a happy smile.
I am sick of it.
They are rude but why do we have to be good and take care of them gently?

I have begun to work again in my previous restaurant recently.
I had tried to be good until I went to Canada there but it was so stressful.
I have been supposed to be very talented at doing fake smile since I was a kid, however, I cannot do it at all now.
To keep doing fake smile is too stressful, I found that.
So, I try to do less smile than before these days at the restaurant while working there.
But to do it is already one of my habits.
Frequently this habit comes out but every time after I do it, I feel tired.
I feel like I am killing me mentally by myself.

Return to the theme.
As fake smile, being polite against rude people is also one thing that I cannot tolerate anymore.
Unless Japan created Keigo culture, it would not happen.
I believe a few polite expressions are fine because English has that too.
Could you, would you… like them.
But Keigo is too much. Why did our ancestor generate that? That is insane.
There are 3 sorts of Keigo expressions. I even do not remember well though.
I wish we did not have Keigo.

But probably they have reasons why they became rude.
I guess they have stress as well like me.
They have been living under the pressure longer than me and they have to use Keigo in their personal life for their manager or chief.
They want to feel they are king or queen in their life, sometimes.
So they look down on us, like me younger and shorter than them.