Is it okay to produce products that you don't have patents on?

In fact, you can do it if you want, but when you buy it, you don't want every detail to be exactly the same as others'. You have to make minor changes, so you can't sue for infringement.

For example, there used to be Ding Xin chicken, which is a patent, but now there are any Luding chickens. In fact, all chickens are the same, but the names are different, so it is not infringement.