Hope this helps:
Option 1: 70 Mail / Garmin or other
Advantages:
Records in 2.7k Video that one can crop without loss for 1080p videos
Has Decent Night Mode
Decent Wide Angle Video as well
Its your normal Dash Cam that you are re-purposing it for action cam - always present in your car and always recording.
Latest Gen 70mail records GPX data as well so if you want to overlay that in your video you can do it as well
Heat resistant - I have never seen my camera stop because of heat (a. because of the smaller sensor, b. no battery c. the way they are made).
Cheaper than other video cameras (bar repurposed phones)
No need to remember to record anything - no planning needed
Disadvantages
You wont get 4k Video and not too good optics.
fixed place to mount - only one on the dash
Single purpose use.
Mine does not capture gpx data so I use Gaia data to overlay on my videos (if I ever do it that is)
Dash cams don't show the action as well as an action cam can, somehow I feel they show the video slower than they are.
Option 2: GopPro/Sony/DJI Action Cams
Advantages
Higher Resolution up to 4k
Better Optics & image stabilization plus upto 240 fps or timelapse recording
GPX data recoding and easy to overlay on videos
Can be mounted on many different locations and they are generally waterproof using cases. You can use it for other than drives as well.
Possibility to live telecast on social media with some devices (gopro does it).
Disadvantages
More expensive compared to a dash cam also you end-up buying into the whole ecosystem.
Gets hot quickly and in summer it might stop working
You have to remember to record and have to plan according to your drive.
Option 3: Repurposed Phones (Jugad)
Advantages
You already have it - no cost you can use your current phone as well.
Decent quality of video and if the phone is not too old it will do 4k, Slowmo and Timelapse as well
You can live broadcast on to social media for your drive.
Disadvantage
If it is your daily driver you may get some unexpected calls which will stop recording (no issue if it is unused)
You need to securely mount it inside the car (same as dashcam) plus it will be more obstructive for the view than dashcam
It has batteries and they get hot soon. In summer my iPhone gets hot and stops working if it is mounted on the windscreen.
You have to remember to record as well.
I have all of the above and I use all of them. My first preference still be Dash Cam for value for money and convenience point of view. They wont be the best but they are there when you need it.
The logical way to go is to use your phone first then get a dash cam and finally an action cam.
In DashCams I prefer 70mail they are not too expensive and work well and in the newer models they record front and back.
In Action Cams - I will recommend the latest GoPro it gets refreshed every year with new features being added. DJI has come up with a new lineup you want to check. Sony - they had good action cams but have seen a refresh in the near past. You might be able to grab a 2nd hand one if you can for all of the above as well.