This video explains how you can hide or rename or change positions of SharePoint List command bar using Json.
This video explains the steps by step process of hiding command or ribbon buttons without writing any code.
Sample json :
{
"commandBarProps" : {
"commands": [
{
"key": "new",
"hide": true,
"position":2,
"text":"Add product"
},
{
"key": "editInGridView",
"primary":true
}
]
}
}