But pipepipe runs on my phone and it's open source, so it's possible it has access to free infrastructure to build and distribute. I still don't understand which costs you are talking about. Is it YouTube's for storing and serving videos?

If this is the case you need to understand that all this is happening because YouTube is a monopoly. They lock-in creators and their userbase by requiring daily updates without which the algorithm won't promote the creator. This is surely to increase video volume, thus views and ad revenue, but a side effect is that effectively the content creator has no time to try to move the user base to another platform.

YouTube is a monopoly and one that's already abusing its position. These alternative apps and adblockers/sponsorblock hurts Google and it's good, a monopoly needs to hurt in order to break.

But the most important thing to remember is that this is self inflicted. Google could have played fair and opened up competition and instead of building a fortress they could have just... invested in making a better product to compete as it's how capitalism works. Monopolies destroy capitalism so it's morally justified for us citizens to club monopolies into smithereens by resisting corporation mandates.