Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

This is laughable

How so?

I've been on a few different private trackers since the early 2010s and I had 1-5mbps upload for like a decade and I've never had any issues with ratio on any of them

I've been in numerous private trackers and all of them offer bonus points from seeding that you can use to 'buy' ratio if people aren't downloading from you. You might also ensure that you have port forwarding setup if nobody is ever connecting to you because even though I rarely ever get a lot of seed ratio, I usually get something on most files and this is all through my home internet connection.

I've determined it's basically impossible to do that if you don't own a dedicated high-bandwidth seedbox

Completely untrue. I don't have a seedbox, never had one, and I keep perfectly fine ratios on two different private trackers. One has a ratio of 56 I think, the other (the one I use the most) has a ratio of 4.5, both just have a minimum requirement ratio of 0.5 i think before you're kicked.

I just have a computer on my home network, which is also the media server.

Your assessment is correct for particular private trackers. I belong to several and they all operate in different ways with different rules. What you are describing is my experience with trackers like TorrentLeech, my least preferred tracker. But on the other end of the spectrum is a tracker like Seedpool, where it is very easy to maintain a ratio just by keeping your client online with some data available.

Private trackers can be very accommodating and useful without a seedbox. Just find one that suits you. They are not all the same.

I prefer private trackers that permit cross seeding and decent rewards for making data available over time (in lieu of focusing just on how much data you transmitted).

Several trackers also freely give data buffer just for interacting with the site on a regular basis. Some have simple daily tasks like commenting or thanking an uploader. Others just want you to click a button and voila, you have 20 gigs free to use everyday.

Massively depends on the private tracker. Some have a hard economy where you must seed every byte, but there are plenty of trackers that have bonus points based on seed time and torrent size which you can exchange for download allowances.

Some easy to get in trackers are torrentleech and seedpool, AFAIK both of them have open signups occasionally.

Actually joining is the easy part.

Building ratio is the commitment and major hurdle. It's costs a bunch of money or time. A years long project. That can be shortened with money on a seedbox like you said. But it's a project you only need to do once. I did it a couple decades ago. Now I don't think of it. I can get almost anything at any time. It's absolutely worth it.

this is very much untrue. I've just got a home connection and manage fine.

That is not true. I have a home server on a mid level connection, and it works perfectly for maintaining ratio as long as your ports are forwarded correctly so you remain connectable.

Ive got a Raspberry Pi (from back when they were cheap) and a USB HDD that chugs along just fine in the background. My upload speed is utter shit (rarely exceeds 1MB/s) but I've still uploaded terabytes of data. All you need is the ability to just leave the server running in the background.