No, most people don't care about having this battle - that's the point. If there's no demonstrable reason to leave (e.g. "former president got banned from major platform, so go to new platform") then the - valid, if personally boring to you - point is: how will you persuade people to leave it?
- No ads.
- Free, even for business-use.
- No algorithm interfering with visibility.
- It's usable by community members who do not have a Facebook account, for whatever reason.
- Allows for more free-form content.
- More choices for content delivery format & notifications (say, email, text message, newsletter links).
Maybe you can come up with some. What would you find to be a convincing argument to switch to a community-owned organization platform instead of Facebook?
Honestly if it really would just need to cover the price of the cheapest hosting you can find and the domain registration a single small-to-medium Adsense ad in the sidebar might generate enough to cover it. I don't know how many impressions/pageviews it takes to generate $20 but it can't be that many.
I run some meetup groups, and still pay for it for now, but the price hikes and other charges they're adding are onerous. I know many groups who have shutdown, and I know of some other players wanting to get in to this space to take over from meetup.com. $10/month to run a smallish group is affordable for a lot of folks. $50/month is not. $300/year is just not worth it to many folks, but... $99/year would be. Meetup seems to be moving in to some weird 'hyper optimize for short term revenue' move, which makes me think they'll be gone or acquired/dismantled in the next 5 years.
Simply put you have to ask the most important questions first, then build an app backwards from that
1) How will it be paid for
2) How will it be moderated.
So, you've already failed number one. You have no means to pay for it.
Then you failed number two. If it gains even a modicum of popularity it will be completely and totally over ran with spam.
There are things you should not try as you can easily deduce that they are not rooted in any reality, e.g. "free" and "no-ads"
The internet is a horrifically hostile place. If you design a product without that in mind you're creating a danger for yourself and for your users. Slap a community site up without thinking about COPPA or GDPR or whatever Californian law and suddenly you'll have problems. Slap a site up without heavy moderation and it will be filled with the most awful porn you can imagine.
It's not about just accepting the way things the way the are, it's avoiding becoming a casualty of the way things are.
That is also true of every advance society makes: Most people are happy the way they are. It's an obstacle every innovator and leader faces. Yet somehow, we make changes and advances.
I was part of something similar a few years ago at a local makerspace. We were using Meetup.com for a while then someone relatively new suggested we try using Discord instead. There wasn't much of a convincing reason besides "let's try it", so a bit over half of the active people gave it a shot, and everyone else followed since that's where the activity was.
While a few people were initially grumbly over making a new account, there aren't many complaints now that we have bots to help with calendars and a bot to help us monitor equipment.
It might happen again. :)
it does seem unlikely to work though, for the reasons you mentioned