GPS inaccuracy is half the problem, and yes causes people to create extra segments. I’ve even done it where I’ve confirmed my trace is actually pretty much spot on but the original that was created was actually way off and sometimes it would match mine and most the time not and likewise missed friends out who were on the same ride, so I do one marked as “alternative match”.
As said it doesn’t really detract from the enjoyment of Strava. Only thing that niggles me really is where a new trail is put in nearby or replacing an old one, quite different trail but the segment leaderboard is showing people who road it years ago. They need an option to expire a segment or to mark one as starting from a particular date. Still though I generally set the leaderboard stuff to just show friends so it doesn’t matter and I’m not using it to compete anyway, just out of interest.