I use a Pixel 6a running GrapheneOS, which as a default comes with almost no apps (awesome!).
So for me this isn’t about using the default apps, because this would be a very short list.
Here is the list of apps I use (on my phone):
📧 Mail Client: Vanadium browser
📝 Notes: Obsidian
✅ To-Do: Todoist
📷 Camera: GCam
📷 Photo Management: Built-in gallery, folders on my computer
📷 Photo Editing: Snapseed / Image Toolbox
📆 Calendar: Agenda
☁️ Cloud file storage: filen.io
📰 RSS: BazQux Reader
🌍 Maps: Organic Maps
🌐 Browser: Vanadium
💬 Chat: WhatsApp, Signal
🔖 Bookmarks: Raindrop, Pinboard
📑 Read It Later: bookmarks in the browser, emailing things to myself