Some Internet providers have different rates for different capacities/bandwidth. Last time I used COMCAST, their wizard walked you through different use-cases and you got different packages based on the type of stuff you said you used it for.
My thinking was that the landlord would be providing the same internet either way, work from home or no, and it costs the same whatever happens. Sure, you'll maybe use it more if you're working from home - but that costs exactly the same as, say, not using it at all.
(It is possible that the landlord will note that you ticked the WFH box, and spend part of the extra $200/mo on upgrading the broadband at the property to 900 Mbit/sec fibre or whatever. But I just don't think this very likely.)
How is Comcast a poor example? It is a major internet service provider in the Bay Area and in some places is the only one available. For better or for worse, you have to go with what is available in your area.
The point is - they have different plans at different rates (prices) and they base it on what they believe you use it for. So you can’t just be dismissive of someone thinking that internet access for someone who works from home might cost more than if you don’t work from home. It may be wrong but it is logical and possible in the usecase/context being discussed
Comcast does data caps everywhere except places where its customers have alternatives. It's insane that they're allowed to charge monthly for providing a speed and then also set the data caps at like ~3h of continuous full use.