It's not that hard which is why it's weird that you're being so aggressive about it.

If they offer the one show that you want to watch somewhere else than your incentive to subscribe is 0.

If they don't then you have to subscribe for at least a month to watch it. That is when they try to hook you with everything else they offer so you stay on for multiple months.

They don't care about making more upfront because they can make more in the long run by getting people into their platform and keeping them. Which they have been very successful doing.

Most other streamers allow for purchase because that's what they did before they entered streaming.