Even in the water filter scenario, let's assume everyone has this fridge and is regularly buying filters. They had temporary growth in revenue but now that everyone has fridges + filters it's mostly stable again.
Do you think they'll stop there? The unsustainable idea we have of running a business would suggest they should be doing something else to even further increase the profits.
The name-brand GE filters (for the type I used to buy) eliminate/reduce lead, chlorine, plus "5 trace pharmaceuticals" and 15 other contaminants.
The bargain bin filters (HDX, in this scenario) only eliminate/reduce lead, chlorine, "tastes and odors."
GE - https://www.homedepot.com/p/GE-Genuine-MWF-Water-Filter-for-...
HDX - https://www.homedepot.com/p/HDX-Water-Filter-for-GE-Refriger...
If you can demonstrate that the store brand filters are the same, despite not advertising the ability to filter the same chemicals and pharmaceuticals then sure, you win.
My point was that the “name-brand costs more for no reason” is not always true. FFS
I have no interest in buying and disassembling the filters to compare them but since they are both charcoal filters they are the same. If they were not, then one of them would be advertised as a charcoal filter and the other one would be advertised as a charcoal filter + some other filter.
On this water filter thing, the fridge costs about $1500. Suppose it lasts 10 years, and you replace the $55 water filter every six months. That's $1100 worth of water filters! The water filters almost double the cost of the fridge!
Profit-wise, on a $1500 fridge, it's a competitive market. You're looking at multiple brands, so GE probably has a profit of $100 at most on the fridge. On the water filters though, we know that the generic one sells for $19 and the branded one is $55. That suggests that GE probably makes a profit of at least $20 on the filter. Over the life of the fridge, that's $400 in profit -- 80% of the profit of the fridge is in the filters! If third parties are threatening that profit by making knockoffs, of course GE is going to take countermeasures to protect 80% of their profit.