The only drawback to DM rewards, is that some players may feel outclassed by a higher level character at their table. This in and of itself can be somewhat mitigated by simply not using DM XP to the point where you grossly outclass other characters.
Other than that, the only other issue I can think of is that some players may complain that their X level character has less gold than the DM character. This too isn't as big a problem as people are making it out to be, given the fact that same DM character played less adventures and therefore the other characters at the table are likely to have greater renown than the DM character, plus also a greater opportunity of having gained special story rewards, and unique treasure rewards (eg. mounts, shield guardians, and the like, depending on level).
Ultimately, my opinion on the matter is, if players are complaining about the amount of gold a DM character may have compared to their equivalent level character - I would a) remind them that their equivalent level character has +X renown & story rewards, and b) nothing is stopping the player from stepping up to DM themselves.
Speaking personally, I don't think the rewards are disproportionate to the effort needed to obtain them (unlike in earlier seasons when DMs complained at how pitiful the rewards were).
