There's so much more they could do to improve the service instead, but then they haven't shown any interest in development for years. I guess this is the easiest way for a desperate management to try to squeeze some more money from the users fast. It's not a good sign for Strava users, even if they don't use the features.
The biggest loss for me (if I wasn't subscribing) would be the "friends" leaderboard. I'm actually not that much interested in the obvious peer ranking on my home climbs (I already know how strong each of my cycling buddies are), but it's also a bit of a connoisseur feature when traveling (e.g. when it's not 2020): a famous col will have dozens of friends on it and none of them are even close to top 1000. The stories (when, why) are often more interesting than the times, even more so if it's not a famous col by a hidden gem, which then becomes a bit of an asynchronously shared experience.