Strava

but why strava do it, I have no idea

because they're trying to pivot to being more a social network. Also algorithmic feeds never end, so when the adverts come you will keep scrolling and see more adverts, rather than getting to the end of the day and stopping.

Basically just look at how Instagram has gone to shit, that's exactly what they're doing, they even hired an ex high-up Instagrammer.