Switching from iPhone to Android is not as painful as Apple would like you to believe. The main friction points are photos, messages, and the habit of reaching for iMessage. Everything else migrates cleanly.
Photos: if your photos are in iCloud, download them to your computer first (iCloud.com → Photos → Select All → Download), then upload them to Google Photos. Alternatively, use Apple's Data Transfer tool at privacy.apple.com to move photos directly to Google Photos — it works well and preserves original quality.
Contacts and calendar: if you use iCloud for contacts and calendar, export them as .vcf and .ics files from iCloud.com and import them into Google Contacts and Google Calendar. This is a one-time sync; going forward they live in Google.
Messages: your iMessage history does not transfer, and this is the one thing Apple hasn't made easy. Accept the loss. New conversations on Android use Google Messages with RCS (which is end-to-end encrypted and very good) or Signal if you've made the switch already.
The day you switch: turn off iMessage on your old iPhone BEFORE you get your new Android. Settings → Messages → iMessage → off. If you skip this, your texts from other iPhone users will go to iMessage (your old number) instead of your Android (your new number), and you'll miss messages. This is the single most common mistake in an iPhone-to-Android switch.
Apps: most major apps are on both platforms. The exceptions are Apple-only (GarageBand, Final Cut, Logic, some games). Google alternatives (Gmail, Maps, Drive, Photos, Docs) are usually better on Android than their iOS versions anyway.