Across 3 VPN providers I use, none of them have issues accessing reddit anonymously. There are nodes/regions that are blocked, but finding a working server isn't hard.
Care to name them? I use Mullvad, and I love them, but their exit nodes are routinely blocked by Reddit and streaming services.
Might be you're logged in? I often hit a block when using (proton) vpn if I'm logged out but not otherwise.