The problem with this question is that it's a whole lot more nuanced than "Do I need it?". In short the only time you could possible benefit from one is if you use torrents, and even then it's really only public torrents. From there it depends on whether the swarm is monitored, and given how you simply can't know that it's safer to just assume that it is. But even if it is, will your ISP bother to forward the DMCA notices to you, and if they will, will they care if you take no action?
If you check enough boxes it's likely worth it "just in case", although at that point you might as well look into debrid services.
No idea how many seasons there are in total, but I can find 6 on TL.
How much, with what budget and for what use? Something as simple as a seedbox could suffice in some cases, otherwise maybe look at Hetzner's storage options.
Doesn't really matter what it may have once been considering we're talking about using it to store and distribute large binaries of today. And yeah, six figures doesn't sound that far off the target when you consider the storage in petabytes and, more importantly, the bandwidth. Multiply that with redundancy and multiple locations in general and you'll easily hit six figures.
Check the activity requirements and try to stick to them. You might end up wanting to use the site later down the road.