Exactly, there are altcoins with unlimited block size, for example BSV. There are many useless data (for example weather data from the past), so adding this text will not make much difference, because such blockchains are going to grow into insane levels anyway.
Just to clarify, BSV isn't unlimited block size. I think it's capped right now at 2GB which they hope to increase it to 1TB in the future. But even then it's not "unlimited".
If your PDF is similar in size to the Bitcoin whitepaper, it will take around half a BTC, not sure if you want to spend this much to store a shitty PDF in the blockchain.
I would think that's a bargain in one sense. that is if they could develop a tool that let you browse the blockchain and see the stuff stored there as easy as firing up a web browser and typing in a url.
There are much cheaper ways to store something in a way that is tricky to take down, like torrents, self hosting and similar.
yeah but those are only semi-permanent. one would presume that storing on bitcoin is about as permanent as you can get. They do have filecoin but you have to pay for time-based storage. then if you don't renew they will drop your files like a hot potato.