解决方式

1.添加 babel

yarn add @babel/preset-env --dev

2.添加版本限制

//babel.config.js
// babel-preset-taro 更多选项和默认值：
module.exports = {
  presets: [
    [
      "taro",
      {
        framework: "vue3",
        ts: false,
        targets: {
          ios: "9",
          android: "5"
        }
      }
    ]
  ]
};

3.添加es转换

//  config/index.js
h5: {
    webpackChain(chain, webpack) {
      chain.merge({
        module: {
          rule: {
            myloader: {
              test: /\.js$/,
              use: [
                {
                  loader: "babel-loader",
                  options: {}
                }
              ]
            }
          }
        }
      });
    },
    publicPath: process.env.NODE_ENV === "development" ? "/" : "./",
   }