There are different types of highlighting:
1. Syntax highlighting (place cursor inside variable)
"editor.occurrencesHighlight": false
2. Selection highlighting (similar chunks in document)
"editor.selectionHighlight": false
3. Matching brackets highlighting
"editor.matchBrackets": false
There’s a second way – make them less obtrusive (or completely transparent):
"workbench.colorCustomizations": {
"editor.selectionHighlightBackground": "#0000", // similar selection
"editor.selectionHighlightBorder": "#0000",
"editor.wordHighlightStrongBackground": "#0000", // syntax variable assignment
"editor.wordHighlightStrongBorder": "#0000",
"editor.wordHighlightBackground": "#0000", // syntax variable
"editor.wordHighlightBorder": "#0000",
"editorBracketMatch.border": "#0000",// brackets
"editorBracketMatch.background": "#0000",
}