I’m not that person but I’ve noticed this pattern in such people. Rent-seeking is anything they don’t like. So it could be landlords charging tenants rent, it could be Apple charging developers 30% “rent”, could be Google charging “rent” on the ad space next to search results, Microsoft charging for Windows even though an additional copy of Windows doesn’t cost them more to produce.
Basically it can be as broad as you want it to be. And these delusional folks say we can stop it by “not letting it happen”. Lol.