It's something of a formal fallacy in gaming: If some pen-and-paper game systems are too complex for some players, then physical representations of game components must make a game easy. Of course it's not entirely wrong. In a way, this is why miniatures exist, and why [theoretically] useful products like spell cards and health trackers exist. After all, a player with a spell card is a player that doesn't have to open the rulebook to the Spells section and look up the spell. A player with a health counter doesn't have to search a character sheet for where they've written HP. A player with physical coins to represent wealth doesn't have to do any accounting.
However, there is definitely a threshold for how helpful physical components are. If you eliminate the character sheet (or army roster, or profile, or similar) and replace everything with physical tokens and dice counters and cards, you've only displaced a player's mental workload. Instead of hyper-focusing on a character sheet with values written in, the player must focus on piles of tokens and coins and gems and cubes and stacks of dice.
In fact, not only has management not been reduced, in many ways it's been made more complex for its tenuousness. It's hard to accidentally erase a number from a sheet of paper and write a new one in, but it's frighteningly easy to brush aside that stack of plastic gemstones tracking your action points. It's easy to fold up a character sheet at the end of the night and put it into your RPG notebook, but it's cumbersome to gather gaming detritus into a ziplock back and then reverse the process before each game.
Worse still, having too many physical components to track means the game designer can't introduce a physical trackers where it would actually make a significant difference. Suppose you're designing an ability that's a little too powerful to allow every turn, so you need to limit its use. To help players track when the ability has refreshed, modern game design has several common conventions you could use.
Any of these subsystems loses value when it's one of 5 or 10 different subsystems. A physical tracker is effective because it stands out from the other things a player must manage.
Every subsystem requires interaction and mental cycles. As a designer, it's important to be conservative with the budget of a player's mental capacity. If combat abilities are constantly being exhausted and refreshed, then maybe that's the resource you want to "spend" a subsystem on. If a resource is strictly limited to a specific quantity, then maybe that's the resource to emphasise with an interactive subsystem. But when a value rarely or never changes, or when it can be represented through mechanics that happen anyway, then it's probably best left to a data card or persistent rule.
For example, tracking ammunition is officially one of the most tedious game mechanics. Nobody wants to do it, everybody forgets to do it, but also most of us would probably admit that it can be a powerful mechanic. Maybe a physical tracker is the answer.
The first (sub-optimal) attempt at ammo tracking is the most obvious. Each weapon has an ammo value (x.) When you acquire a weapon, you also get x number of tokens. Each time you make an attack with the weapon, discard 1 token.
That's really simple and very understandable. It would add tension to game play because it reinforces that ammunition is a consumable item. You want more ammo? You'll have to find it or buy it.
However, this tracking system requires you to be diligent. In the heat of a battle, you're ideally going to be so invested in the game that you'll forget to interact with your ammo tracking system. In a way, the system competes with the game it's meant to service.
Doom the Board Game solves the problem brilliantly by building the ammo tracking system into a standard dice roll. When you roll the game's specialty dice to make an attack, you're out of ammo when you roll a bullet icon. For games that don't use specialty dice, maybe the roll of 1 means ammo has been expended. Either way, it's built into an action you're already doing to play the game. Instead of distracting you from gameplay, it emphasises complex choices, because sometimes it's safer to attack with a weapon that doesn't use ammo rather than risk an overkill that uses up a precious resource.
When you use a subsystem for every system in the game, everything becomes equally significant. Your action points are as important as your health, which is as important as your ability refreshes, which is as important as your skill ranks, and on and on. Games track a lot of information, but when the game itself is designed to assist with tracking data, it's easier to play, and a lot more fun.