I should note that my scenario was exactly the same. I wanted to share location with family. Additionally, Traccar supports temporary location share links for friends if you'd like. You'll need to self-host it- I personally set up the Traccar server inside kubernetes and used Traefik for reverse proxy and SSL, but this is not necessary.

The nice thing about Apple's Find My is that it runs in the background but only checks and sends your location when someone is actively looking at your location. Do these do that as well? I've tried Telegram's location sharing before and it drains battery like crazy because it keeps the GPS receiver always on.