Some reasons (not necessarily applying to me):
Countries like Iran/Cuba/NK do not have any trade with the US. Its impossible to get the content legally. Seedbox paid for with BTC would allow them to download what they like without the government knowing it. These are not "lost" sales.
Even Saudi Arabia, despite having ties with the US, doesn't allow the sale of so much US content (e.g. ideological books, NC17/adult movies), and bans VPNs. For citizens there, Seedboxes are the only way to get hold of that content. These are not lost sales either.
Someone with a family and many kids who like movies can't and will not spend hundreds of dollars a month on movies/music to satisfy their entertainment desires when they have other things to worry about like putting food on the table. If they don't pirate it, they won't buy it. At best its a single lost sale, out of the dozens they download each month and make their kids happy despite the other difficulties they have in life. These are not lost sales either.
Software pricing isn't adjusted for local income levels. Something that costs 100$ means 10 hours at most of work in the US. In other countries, 100$ can be 2-4 weeks worth of salary in the "3rd world" countries (is that term still allowed ?). No one is gonna pay for Windows/Office/Photoshop in those countries anyway. If they can't pirate it, they would use the open source ones. No one will accept to double-triple the price of their new desktop computer because of software when they've already spent many month-year to have enough money to ask the shop around the corner to assemble them a desktop with Walmart-level specs. These are not lost sales either.
Fragmentation. If you want all the content, you need to have Netflix, Disney+, HBO, YouTube Premium, iTunes AND physical media from Amazon (do you even have a DVD/Blu-ray player ?). The hope that Netflix becomes a one-stop-shop vanished a long time ago. Netflix is only good if you like them to dictate what you'll watch. If you want the same content as torrents offer, for a movie that you'll watch one time, you might end up having to pay hundreds of dollars per month in subscriptions only to have one movie/series from each channel per month and not use the rest of what the distribution channel offers.
The music industry got its s*t together and iTunes/Amazon Music/Google Music/Spotify all offer all the music in the world for a small monthly subscription and there is no need for piracy. The movie/TV industry on the other hand is just moving in the opposite direction making it harder and harder to have a single useful subscription. Each content owner wants to put their own hands in the consumer's pocket.
The list goes on and on.
Now, you're right. A good amount of those who pirate content can afford it, but without those being involved, the rest who can't obtain the content legally wouldn't be able to get into the party.
Its a very complex question, but keep in mind that piracy existed since the very first days of software and music and these companies survived just fine.
For the cinema industry its more complex, but at the end of the day most people who visit the cinema do so because of the experience rather than to just watch a movie. No one is gonna say no to going out with their friends to watch a movie because they can get the DVD rip for free from a torrent, or refuse to sit with their family and watch a new episode of a TV show on their cable because their pirated it the night before.
You have to broaden your vision my friend and look at piracy from more angles than just the 30 yo male adult making 100k/year who pirates movies instead of paying for Netflix.