There is no doubt that money counters are among one of the most powerful counters in the game. Most of the damage dealt to opponents comes from character swings, and the money counter puts a complete stop to all soul damage dealt by these attacks. Furthermore, any reverse damage abilities are directly nullified as well, turning a dangerous lethal hit into a passive afterthought.
Are money counters still valid profiles to be run in the current metagame?
The brutal reality is that, by the time that money counters are online, most effects that push for lethal damage have been tied to abilities that trigger during the start of the attack step or even the climax phase. Sure, the money counter can deal with the aftermath of the character swing, but the damage usually is already dealt. The problem with money counters is their requirement of targeting a character in battle makes them difficult to use as well.
Conversely, rest counters are still quite solid options in the game due to their ability to target other characters outside of battle, ensuring that, at the very least, another instance of a combo can be denied. Rest counters are also much more accessible versus money counters as they are usually in the form of character backups nowadays rather than events.
Are rest counters completely useless? I would disagree. Even if you do survive the multi-hit combos that occur at the start of the attack step or climax phase, the last big swing can be a deciding factor on whether you survive that turn. They can still be used as a measure to prevent that; however, in comparison with rest counters in the current game, they are really more of a niche.