TLDR: I prefer cryptocurrency because it retains privacy for both parties and does not rely on third-parties that profit heavily off of their monopoly.
Few people think about donating to tools and software that they
use regularly. I'd say that a decent amount of the people that
profit the most from tools like OBS Studio have ever even
considered giving something back. I obviously have no source
for this, so it could also be that most do in fact donate and
never mention it or do it anonymously. Ultimately I can only
really speak from my experience.
Even fewer people even go through the trouble of finding out if and how they can contribute, so if you've somehow ended up here you're already part of a small minority. I don't keep any logs or use analytics so for all I know nobody has ever even opened my donation link. If you've ended up here you werent completely deterred by the fact that I only accept dontations via different cryptocurriencies. I did at some point accept donations via other means, but this compromised both my and other peoples private information, which is not something that I'm willing to do for a few dollars. I also do not want to use PayPal and other payment processors as they are all centralized systems and I want to limit my dependence on them as much as possible. PayPal has made some strange decisions in the past and there's no guarantee that they won't get any more funny ideas in the future.
So instead of just not accepting donations at all I decided to at least offer the option of being able to send different types of cryptocurrency to the wallets on my donation page. I know that the mere mention of crypto boils some people's blood and that a lot of proponents of it range from annoying shills to just plain scammers. The problem is that there's no real alternative that solves the issue of privacy and centralization for me. Anyone can send donations from anywhere to these wallets without any strings attached. As a bonus you can also always veryify how much money the wallets (except for Monero and ZCash) have received and determine if a project has already gotten enough donations. The downside is that most people do not want to spend extra time figuring out how this system works and would rather use something they're already familiar with, which is understandable. As I said, few people donate to software projects, even fewer would want to go through extra steps to do so.
Ultimately this mostly just means that I'll get less donations, but I'm willing to accept that. If you've made it this far I thank you for the consideration, even if my insistence on using cryptocurrency deters you from donating.