I’ve migrated away from all of these on-line tools as I don’t think any of them are really up to the task.
Currently I use a PMC spreadsheet (of my own design) and WKO4 via a free Trainingpeaks account, to make syncing more straightforward.
WKO4 has every tool I could ever need for analysis but isn’t great as a planner - adding stuff in the future isn’t a nice drag and drop like in TrainerRoad or Trainingpeaks, so to cover that I use my spreadsheet where it’s really easy to add future daily TSS to see how things look over the next few months. The only problem with that is keeping the spreadsheet up to date is a manual process. Not the end of the world though.
Strava is just a social media platform that serves as a sync service with a couple of nice to have features for planning routes. I’ve recently signed up to Komoot and like that so… I pay for premium as a way of supporting the company rather than because I need any of the premium features.
Trainingpeaks is fairly limited in as far as how much it can be configured and, as a WKO4 user, there really isn’t much point in having it other than in it’s free form to sync to WKO4.
For me the analysis features in TrainerRoad are half baked and although the calendar is great for planning, without a proper PMC, I’ve found that it’s pretty pointless for me. I could use it, but what’s the point then you can spend a few hours making a spreadsheet and have a fully functional ‘industry standard’ way of looking at training stress. At the moment I’m just using TrainerRoad as a way of reliably using power match to run my own custom workouts. 
Cool company though so they can have my money.
Tried Xert a few times but couldn’t get on with the black box approach.
Garmin Connect and Polar just serve as ways of getting information off my devices.
Mike