It's a hobbyist computer/learning platform whose biggest draws are price and community support. Demand/support isn't flagging so performance and connectivity doesn't seem to be an issue for the target market. The biggest community wishes were answered, more USB ports and bundled wifi. If the RPi can't keep up with what you're doing there are plenty of other more powerful and more expensive options out there.
There are plenty of more powerful and cheaper options too, it's just that the Raspberry Pi has mindshare amongst people writing about hobbyist and maker stuff. I have decidedly mixed feelings about the Raspberry Pi community as a whole; while they're certainly vocal and numerous, they used to have an unfortunate cultural tendency towards blaming any problems on the users being too stupid to use a Pi, even ones caused by major bugs in the Pi itself.
Wondering if you can link some examples of this? Genuinely curious. I've been using the Pi for some for-fun projects lately and haven't encountered limitations caused by the platform just yet so I haven't experienced this (yet? hopefully ever?).
Orange Pi and ODROID-C2, and there are a few slightly more expensive but vastly faster and higher specced options (like the Tinker Board). But the onboarding experience and ongoing support is usually far worse than with the Pi.