Hi,
Generally speaking both Voltage Regulators and Voltage Reference are used to generate a regulated output voltage that is ideally independent to the change in load current, input voltage, temperature, etc.
Voltage Regulator usually provide higher output current than a Voltage Reference but they are much less accurate than a Voltage Reference. The output noise level is higher in Voltage Regulator compared to Voltage Reference. Moreover, the long term stability is not specified in most Voltage Regulators.
Considering the above facts, can we say that Voltage Reference with a precise OpAmp based Voltage Follower is better solution as Voltage Source because this solution would be more precise then normal Voltage Regulators and can also deliver more current as Voltage Regulator normally do ?