Limiting the player isn't inherently bad. The game rules limit what the player can do all the time! You're usually limited to how many spaces you can move in a given turn, what kinds of actions you can perform, and so on and so forth. Weight/encumberance should be treated the same way: limit the player's choices in a manner that is strategically and/or tactically interesting.
The standard use of weight and encumberance is to give every item a particular, universal weight, all of which combine into the "inventory weight" of the player. The player becomes encumbered whenever the inventory weight becomes greater than some value, often scaling with attributes like strength, and being encumbered usually causes the player's speed to decline. One might call this a pseudo-realistic approach, because all massive objects will have weight, and surely someone holding so much won't be able to move and/or react as quickly as someone who doesn't. However, as it often the case in games, trying to use a realistic approach tends to detract from gameplay. Thus I would recommend to attempt a more novel implementation.
If you're planning on both using both a hard limit (total inventory space) and a soft limit (too many items makes you weaker) then you should probably try to make them interact. For instance, require that inventory is limited to what containers you bring (backpacks, sacks, chests, purses, satchels, etc), each of which also has a weight. This means that you have to plan out not only what to bring with you, but what to bring that will allow you to carry more as you venture further.
You also don't need to strictly follow "weight" as the means to encumber the player, but use some other metric. Perhaps if a player is carrying too many items of a certain type, it takes longer for them to use that particular type of item. (I have 20 weapons all jumbled together, where the heck is that dagger?) Without necessarily limiting what the player uses, they will likely optimize certain item types depending on what they expect to require in combat. Or you could make it so that carrying too many items makes it easier for them to break or spoil or rust or any other kind of item degradation.
So yeah, I'd stay away from the traditional system if you can and try something that would positively impact the game's limiters.