@TechConnectify here, the quality filter is the human moderation teams. Reporting has uses beyond a user's own instance, because if the report is forwarded to the offender's instance (enabled by default, can be turned off by the reporter), they can take more effective action.

Mas.to can only block the offender from interacting with mas.to, and so can every other instance, but the offender's home instance can affect their behaviour at the source, and also retains their signup details to prevent duplicates from the same address.

We're all used to Twitter's moderation, where cases weren't seen by human moderators and reports tended to go nowhere, but that's not the case here (instances whose moderators don't do their jobs notwithstanding).

"Just mute/block" indeed doesn't help anyone but yourself and tends to feel like whack-a-mole, but escalating it to the moderation teams is what can help others and yourself more effectively. Especially if repeat offenders originate from the same instance, i.e. one with less or no moderation or even dedicated to harassment, those can be isolated by instances severing connections with them and leaving them with nobody but their troll friends.

It's a trade-off: no algorithm to moderate means more work for users and moderators, but less algorithmic overreach, less gaming the algorithm, and ideally, better accountability since all decisions are made (and, if following best practices, documented) by human moderators.

TLDR: It's more work here, admittedly, but blocking isn't the end of the available means, and bringing harassment to the moderators' attention has more chances of curbing harassment both for you and for the wider network in general.

But yeah, I'd be lying if I didn't say, the cost of moderation that's done humanly is more whack-a-mole. That's a trade-off you have to decide to make or not make. It's the price of not having selfies automatically banned for having queer symbols in it, of being able to distinguish between parody and hate, or civility and politely phrased hate.