Maybe it's different where you live, but for me from of the things you listed, the only one that would absolutely depend on a proprietary OS is keeping in touch with friends - because many use services such as WhatsApp that depend on having a phone with Google Play Services. And games where you usually have no choice.
Of the others, many depend on proprietary services, but pretty much all are accessible via their respective websites and I rarely see missing functionality.
payments - just use your card. You could even stick it in your phone case so you always have it if you have your phone
banking - there are some "app-only" banks where I live, but for every one there are 5 normal ones with websites
planning transit rides - all the ones I've used work in the browser
ordering cabs - around here they all have websites... or even phone numbers. Even Uber works via the website.
streaming videos and music - Spotify, YouTube, Twitch etc all work fine in a browser (in fact, on mobile they work better in a browser as you can block the ads!). If you want to host your own, there is Plex and similar.
gaming - most games won't work, but there are web-based and OSS games; Steam Deck could be an alternative
ordering groceries - around here they all have websites
ordering takeout - as above
translating documents - this one is weaker but there are several services that let you do this via the website
getting breaking news - if you really need to see them ASAP, use a site that has an RSS feed - they still exist! Might not work for local news though
taking (good) photos - plenty of OSS camera apps; using an actual camera could be an alternative
reporting vandalism to the city - must be specific to where you live; here everything is via web forms, and if there is an app it just wraps the website