Pick one place to be your master library and consolidate there first. For a mix of iPhone and Android, Google Photos is the least painful long term. On your laptop create a Photos_Master folder with subfolders like 2021/2021-07-04 Beach and copy everything into it from the iPhone and the Android DCIM folders using a cable or your OS photo importer. Before you upload and run a dedupe pass with dupeGuru or digiKam using content hashing and keep the highest resolution copy or the HEIC original. If some shots have wrong dates or time zones, fix them in digiKam and write metadata to files so it sticks.
Install Google Drive for desktop on the laptop, add Photos_Master under My Computer, and check Upload photos and videos to Google Photos so it uploads once without mirroring into Drive. On the iPhone and Android tablet install Google Photos and turn on Backup, and turn off any other auto importers to avoid double uploads such as iCloud Photos or OneDrive camera upload during the migration. Going forward, do all culling and albums in Google Photos, but keep the folder structure as your durable backbone since folders survive any app change while albums are app specific. Periodically export your full library to an external drive using Google Takeout or a desktop sync so you have an offline copy, and add a second backup like Time Machine, File History, or Backblaze to cover the 3-2-1 rule. Expect Google Photos to suppress exact duplicates on upload but keep edited versions as separate items, which is normal and avoids silent data loss. Also disable auto saving from chat apps to the camera roll to cut down on clutter and future duplicates.
