Rent seeking is literally not that though. The word has a definition, and if there's one thing you can't really accuse those corporations of is to basically just extract value without any investment of their own. It's the total opposite, just look at head counts, the amount of money getting spent etc. That alone is basically the opposite of rent seeking, where we expect to see wealth extraction for minimum investment/productivity(and thus, headcount)/cost

More to the point, rent seeking involves taking money for something that provides no additional value in return, usually because you have a monopoly on something that isn't related to the service you charge for.

For example, you own the land so you charge for passage, without building a road or giving back anything or investing any of that money back to create wealth. That makes almost 0 sense for most software corporations. Sure, they might not be profitable but SaaS is basically the opposite since you get the service or a value out of the service directly, and if you don't, there's no reason to pay for it .

I can't think of a lot of cases where a SaaS product is more or less "forced" on you to the point where you continue paying for something that doesn't provide you value. Rent seeking isn't profit seeking.