This is a script that will traverse all your Google Drive files and remove all sharing (owner access only).

remove-all-sharing.js

// Ensure you've installed gdrive first: https://github.com/glotlabs/gdrive

import { spawnSync } from 'child_process';
const delimiter = ';;;';
let files = [];

function getRawFiles(parent) {
    const args = ['files', 'list', `--field-separator=${delimiter}`];
    if (parent) {
        args.push(`--parent=${parent}`);
    }
    return spawnSync('gdrive', args).stdout.toString();
}

function getFiles(parent) {
    const files = getRawFiles(parent);
    return files.split('\n').filter(e => e).slice(1).map(e => {
        const keys = ['id', 'name', 'type', 'size', 'created'];
        const values = e.split(`${delimiter}`);
        return keys.reduce((obj, key, index) => ({ ...obj, [key]: values[index] }), {});
    });
}

function getFilesRecursive(parent) {
    const filesInFolder = getFiles(parent);
    for (const file of filesInFolder) {
        console.log(file);
        files.push(file);
        if (file.type == 'folder') {
            getFilesRecursive(file.id);
        }
    }
    return files;
}

function removeAllSharing(file) {
    spawnSync('gdrive', ['permissions', 'revoke', '--all', file.id]);
}

const fileTree = getFilesRecursive();
for (const file of fileTree) {
    removeAllSharing(file);
}