Last April stats came out indicating that the top four sellers in the world were iPhones, the 13, 13 Pro, 13 Pro Max, and the 12. The SE was 8th or something. The mini didn't even make the top 10 list. By Apple standards, its sales were absolutely abysmal.
It's no surprise the mini has been deleted. Basically nobody wanted it.
At the time, Apple made the Mini because that way they could push the regular 12 price up by $100.
They didn't actually care about making a mini phone, that's delusional.
So the Mini actually served well Apple's purpose.
This time they did the opposite by making a more expensive Plus, no wonder it's not working out.