The simple version is, even if you use a VPN they can still get the MAC address on your computing device, by various means including tricks. Then they can correlate usage of that value with who you are, by comparing data from various accesses. Now, Reddit alone can't do that, indeed they can use multiple data sources in order to cross-correlate. ANYONE who does online gaming will be traceable by this means. The short take is, you are not totally anonymous even with VPN, if you are on a PC. If you are on a burner phone it is harder but if you make even one slipup, you're hosed.

The simple version is, even if you use a VPN they can still get the MAC address on your computing device, by various means including tricks. Then they can correlate usage of that value with who you are, by comparing data from various accesses. Now, Reddit alone can't do that, indeed they multiple data sources in order to cross-correlate. ANYONE who does online gaming will be traceable by this means. The short take is, you are not totally anonymous even with VPN, if you are on a PC. If you are on a burner phone it is harder but if you make even one slipup, you're hosed.