Both practices are effectively drip pricing, is my point. In the case of landlords you're right that there
are a glut of "providers" (and I'm not sure I agree with that terminology per se but mechanically it works), but the thing you have to sift through a horde of ads for one that
doesn't. And even then, it's largely guessing, because they're not actually required to tell you that in the ad itself -- sometimes you have to actually go through the whole
process of reaching out to a human,
maybe getting a response, and
then finding out.
And unlike other up-front costs (first/last/security) it doesn't actually provide value to a tenant in any way. It's a third party that is really only acting on behalf of a landlord, never mind the part where we're talking about literal rent-seeking.
Essentially, it's deceptive advertising, that makes for a less fair and accessible marketplace to consumers. Especially in any remotely competitive rental market (which is a lot of them now, given the way prices have skyrocketed in recent years relative to pay), it's easy to get stuck paying an exorbitant fee simply for lack of a clear way to find out which places don't expect you to pay the third party they contracted.
And that's not a free market either.