the entire saving grace of the fediverse is a lack of algos and curation of your own content. algorithms have basically broken social media and the way we interact with the web. quality and substance is nowhere to be seen for the past few years and many of those who migratate to the fediverse do so specifically for the improved quality of content - it’s the whole selling point.
the biggest reason for subscriptions is. 1. consumer laws don’t protect it. and 2. you can quit your job and don’t have to be actually productive and work for a living because your users will just keep on “buying” the product every month indefinitely. and finally 3. subscription basically gives you monopoly in any given area you host it; because the user will usually not look or even have the means to look for options or alternatives once they have already tied a percentage of their monthly income to a company for the software or service they provide - as wallets got spread thinner and thinner until they, now, are entirely swallowed by subscriptions.
the only people arguing in favor of subscriptions are those who don’t want to work for a living while still taking advantage of the capitalist system.