It's a bit like mobile operating systems. You need to pick your environment and that will define most of the applications you will use. For me there is no doubt, the bible is Strava.
Strava is my repository of all rides I did since 2012 (I used Polar Personal Trainer before - it's discontinued now) and covers 33 different sports at time of writing. Strava is also a community and I'm linked with 263 other members which is really motivating.
As Strava is my environment I linked all other needed software to it. Garmin Connect is needed to download my rides from my bike computer but it synchronizes automatically with Strava.
The Garmin Edge 1030 starts to download my ride as soon as I finish it and Garmin Connect flawlessly sends the data to Strava. I never look at Garmin Connect as everything is in Strava.
For walks and hikes I use the Apple iWatch activity tracker and configured Apple Health so that it also synchronizes with Strava. The only difference is that I need to confirm in the Strava application on my iPhone that I agree to upload the data to Strava. One additional step but you're in control of what's happening.
Another application I'm using is VeloViewer which is based on Strava data.
This application gives me additional analysis and views on data I already have.
I like the yearly progress chart where you can see if you are ahead or beyond the mileage of all the previous years. The segment overview per ride with ranking information is also very valuable.
The last application I use a lot is Zwift. Zwift is the indoor virtual cycling environment for when it's dark, raining or when I don't have enough time. I love it - it's a personal choice - as Zwift allows me to keep the rhythm and also synchronizes with Strava automatically.
Some people consider indoor cycle as a lesser sport. I invite them home (when allowed) to pedal on my indoor bike (I use my previous bike, rear wheel replaced by a Tacx Neo and all connected to an HP PC - what else?) for a while and reserve their opinion for after the trial.
I also experimented with Komoot and Bikemap, with Bkool and RGT Cycling and I'm sure you have a strong opinion on what to use too. Please share by commenting on this post!