There have been threads in this Help Forum about the choice between the use of a mobile phone with the cycle.travel app or a dedicated cycling computer (sometimes called a head unit or just a GPS). As others have explained, your decision depends on your type of riding.

I use Wahoo devices and I thought it might be helpful if I offer some visual evidence to show what this looks like in practice - Wahoo devices have screen record capability. This is what you see on the handlebars as you ride along. These are also my offerings of the most boring videos ever to go on public view.

The route was planned using cycle.travel, and downloaded as “GPX Track” format with C.T’s elevation data. It is 47.7 km (30 miles) mostly in Dorset, and passes along roads with such splendid names as Horsey Knap and Tilly Whim Lane. The turn-by-turn announcements that appear on screen are generated by Wahoo, rather than cycle.travel.

Wahoo Elemnt Roam: The first video shows navigation using the “map page” on a Wahoo Elemnt Roam v2. For those used to the high-resolution screen of a smartphone, this will look odd, but don’t be discouraged: on the small (2.7 inch) screen of a cycling computer on the handlebars at arms’ length, this is adequately clear. The lower resolution is the trade-off for ~15 hours always-on display and weatherproofing.

https://www.youtube.com/watch?v=8u0jyMsXXfc

Wahoo Elemnt Ace: The second video is navigation of the same route on the map page of a Wahoo Elemnt Ace.

https://www.youtube.com/watch?v=RwbWu5ipo3E

I apologise for the duration (2 hours 44 minutes), but these are screen captures of a real-world ride. You could think of this as sakte-TV (slow television).

There are also screen recording methods for other cycling computers, and I would encourage someone else to upload comparable (preferably shorter) videos for other equipment. For Garmin, see for example Shane Miller’s “GP Lama” cycling technology channel, that explains how this may be done:

https://www.youtube.com/watch?v=0DM_aF8oLd4