Your phone already takes great photos. A second camera only earns its place in your bag if it does something the phone can't. For smooth travel video, that's a pocket gimbal camera. For water, snow and rough trips, it's an action camera.
Smooth video: a pocket gimbal
The DJI Osmo Pocket 4 is the biggest step up from a phone for walking-around video. A mechanical 3-axis gimbal keeps shots smooth in a way phone stabilisation can't fully match, it fits in a jacket pocket for markets and tours, and 107 GB of built-in storage means there's no card to lose.
Snorkelling, skiing, rain
A GoPro HERO Black (HERO13 Black or newer) is waterproof without a case, which makes it the one for snorkelling in Cancún or the Caribbean, and it mounts on a helmet, chest strap or bag. Older models go on sale whenever a new one comes out, and either does the job for travel.
Frame it later
The Insta360 X5 films everything around you, so you choose the angle afterwards, and the selfie stick disappears from the footage. It's great for theme parks, boats and city walks, where you don't want to be fiddling with framing.
Batteries and storage
Cold weather and 4K video drain batteries fast, so spare batteries with a dual charger are worth it. Spare lithium-ion batteries go in your carry-on, never in checked bags; camera batteries are far below the 100 Wh limit, so no approval needed. And 4K fills cards quickly: a fast V30 microSD card stops recordings cutting out. Two smaller cards beat one big one, in case one goes missing.
If what you mostly shoot is food, family and views, honestly, a newer phone is probably all you need.
Torn between them? DJI Osmo Pocket 4 vs GoPro HERO13 vs Insta360 X5 →