I can think of a few reasons as to why a website would run ads. I can think of a few reasons as to why a website would limit download speeds

I cannot fathom for any non greed-ridden reason as to why a website would make you wait five seconds before downloading a mod. It’s an inconvenience for the sake of an inconvenience, a problem they made to sell the solution

Of course, we need to keep in mind that they don’t make the mods, they merely host them. Compare the amount of bloat on their website to other, less funded ones such as lovers lab and gamebanana, and it becomes apparent that there’s a money sink somewhere