Is there a limit to how much equipment can merge with your form when you Wild Shape?

Question

So your druid could be wearing hide armour and carry a staff and wooden shield, and various pouches and such, and that would all merge into the form if you wild shaped into a rat or a bird, and that's fine. But if you carry a backpack with 25lbs of gear in it, would that also merge? What if you had a custom heavy pack that could carry 100lb of gear on your back? Or what if you just pick up the backpacks of everyone in the party before you wild shape into something light and tiny? These are examples to clarify what I'm asking with my main title question.

Is there any limit given?

Answer 1

D&D5 says what it means and means what it says. Don't try to overanalyse it.

You choose whether your equipment falls to the ground in your space, merges into your new form, or is worn by it. ... Your equipment doesn’t change size or shape to match the new form, and any equipment that the new form can’t w ear must either fall to the ground or merge with it. Equipment that merges with the form has no effect until you leave the form.

There is no in game definition of "equipment". The OED defines it as "anything kept, furnished, or provided for a specific purpose".

By this definition equipment could be your castle, your rowboat, your bed, your guard dog and your farm as these could all be things "kept, furnished, or provided for a specific purpose". However, in the context of the rules where, among other things, the equipment can "fall to the ground", it must be interpreted as stuff you are carrying.

Anything you wear or let fall to the ground is unchanged and weighs the same. Anything that merges is useless and weightless because it "has no effect".

TL;DR

"Equipment" is anything you are carrying or wearing when you wild shape because ... magic.

Answer 2

Generally I wouldn't worry about it, but if a player is clearly pushing the limits of abusing 5e's generosity, I might limit the amount of equipment to the character's "carrying capacity" (defined on PHB p.176).