Will my backups survive if I lose or change my phone?
Yes, if you are signed in: every backup is uploaded to the website's cloud. On the new phone, sign in to the same account — the cloud backups appear in the list, and any of them can be restored.
Without internet a backup stays on the phone and finishes uploading by itself — when you sign in, when the network returns or when you open the list of backups. The icon in the row shows where the backup is: on the phone and in the cloud, only in the cloud (for example, made on another phone or before reinstalling) or only on the phone.
Without signing in, backups are stored only on the phone and are lost with it or when the app is uninstalled. Such a backup can be saved to a file.
Cloud backups are visible on the website too: your account → “Backups”. How to move your places completely is in the guide on moving to a new phone.