@MililaniVF@glitch.social printer ink has some non-trivial requirements (dry quickly, no smearing) but mostly it's because printers are too cheap

"The manufacturer will make most of its money from the printer cartridges you buy later. Even if the company does make a bit of money from each printer sold, it makes a much larger profit margin on ink. Rather than selling you a printer that may be rather expensive, they want to sell you a cheap printer and make money on an ongoing basis by providing expensive printer ink."

https://www.howtogeek.com/174232/htg-explains-why-is-printer-ink-so-expensive/