Laptop with broken screens for parts are very cheap on ebay.
I recently bought a lot of two broken laptops, all Intel 11th gen for $160. One used exclusively for web browing, zoom, and slack. Another used for coding and building. 16GB each for total of 32GB ram. Use barrier to share mouse/kb between the two.
Don’t trust any apps to handle backup and syncing TOTP keys for you. Gliches happen.
I encrypt and back up all TOTP secret key, which are used to generate six digit codes, to my local offline password store (usb key and paper). In fact, I mostly used my laptop as the second factor because it is more convenient. My phone also has the TOTP key and in case it is lost, I can just regenerate the QR code.