Chartjs-Cannot change anything in chart options

You need to remove the options part in the computed chartOptions prop:

chartOptions() {
  return {
    scales: {
      y: {
        title: {
          display: true,
          text: 'Value'
        },
        min: 0,
        max: 100,
        ticks: {
          stepSize: 10,
        }
      },
    },
    elements: {
      point: {
        radius: 0
      },
      line: {
        borderWidth: 2
      }
    },
    plugins: {
      legend: {
        labels: {
          boxWidth: 0,
          font: {
            fontColor: "#fff",
            color: "#fff"
          },
        },
      },
    },
  }
},