DCs are generally a bad idea, for a lot of reasons

we prefer talking directly to the meter if we can

the data is 'fresher' and more reliable in general

The Legal Instrument is the Meter. So what you need is a meter serial number, a date, and a reading.

If you read through a DC, you are not reading the meter. If you read pulses, you are not reading the meter.

Therefore, the data does not have direct legal authority. Also as for data integrity, there are more links in the chain, creating space for misconfiguration and data corruption.

Also, the DC must read the meter e.g. after midnight on the 1st. IF the HES/MDMS then read the readings from the DC directly after midnight, the readings will not be there yet. When can it read the readings? Who knows. So you maybe wait 2 hours before reading it, and hope it is there. What often happens in practice, is we repeatedly try to read meter readings that does not exist in the DC yet, wasting system resources. So the data is not immediately available if you read it from the DC, but it is if you read it from the meter. If you want real time readings, if you want two way communication to the meter from the operator of the HES/MDMS, a DC will not give that to you, except in the case where the DC act like a router to the meter.

The data from the meter is Fresh. The data from the DC is not fresh.

Another problem with keeping profile data in the DC, is that there is often not enough space to keep as much history on the DC as there is available on the meter. For instance, say you need to read 100 meters worth of profile from the DC: Usually, that would mean that the DC can only keep a few weeks of data in its memory/disk, if you are lucky, perhaps a month of data. So if you cannot read the DC for a long time, the only way you can restore your lost profiles is by going to site and reading the profile from the meters with an optical probe, which normally keep profile data for 3 months or longer.

Furthermore, when using the DC as a router to talk to the meter, all DCs that I've had experience with only allows you to read one meter at a time. When the quantity of meters you communicate with is larger than e.g. 30, for example 100 meters, this becomes a huge bottleneck. When you have such a bottleneck, the concentrator is busy reading meters the whole day. When you then want to switch the meters, the performance is very very slow, since it is already busy. This leads to loss of service to customers, and embarrassment to all involved. What makes the performance even worse, are the following factors: if there are some meters that fail to read in, causing them to be retried repeatedly, making the system even more busy; if there were power failures - minimizing time available to read meters and sometimes the PLC network topology also needs to be rebuilt after a power failure by the DC - that means if you try to talk to the meters while the DC is still rebuilding its network, it causes further problems and delays to the underlaying communication network.

Smart Metering implies real time two way communication to the meter. If you read the data from a DC, that is not real time two way communication to the meter, and therefore it is not real Smart Metering. It is fake Smart Metering.