OTG cable for android - I got mine for something like €2 on ebay. If bluetooth isn’t an option.
The only thing I could see as a negative of TR is that it is purely a training tool - for the most part, but see the disaster day stuff for how the forum is developing the community - rather than entertainment/ game play. So if you just want to get faster, I see no reason to do the other options.
I’ve also ditched Training Peaks Premium as there’s enough analysis and planning capibility on TrainerRoad now, with more to come. I’m only keeping Strava Premium for the ability to appropriate interesting routes easily!