I'm not worried at all about Zuck taking over Mastodon at all, they'll try but they are just so incompetent, because literally every single product idea they have they either stole or bought from somebody else. Great tech, terrible products, zero originality is the Facebook mantra and that is because they have a delusional CEO that they can't fire, because Zuck has delude himself into thinking he's an "ideas" guy like Jobs instead of an "executions" guy like Bezos that he really is, and until he realizes that, he will always fail.
(also, delusional for actually thinking Ready Player One is a good book)
If making a TikTok clone didn't get people to switch from TikTok, why would they think making a Twitter clone is going to get people to switch from Twitter?
The only way I see Facebook being a threat is when they give up on making their Twitter clone and start providing easy subscription service hosting for Mastodon/Lemmy to EEE. THAT would be the time to worry.
I feel like we are seeing lots of these tech companies just clawing at new innovations for profit cause they can't seem to run a stable business otherwise without fucking things up somehow. See the the crypto/nft boom, AI and it's rapid and still somewhat untested and shoddy implementation, etc. We've got strikes popping up in the US as the months go on cause people are definitely feeling the shittification of things in multiple industries including tech and entertainment as of late.
Everything tech companies like meta have been doing in the last several years is looking for their next growth fix to keep their investors happy while running their business like a toddler between sweets.
Elon happened to set Twitter on fire, Instagram is failing to beat TikTok in short form content or even competing with things like YouTube, Facebook itself has been shriveling up over the years, now there's some cool new tech space in the Fediverse and no corporates taking advantage of it - probably looks like early crypto to Zuck if he can swoop in and outpace the open source projects with enough funding.
While you may dismiss Zuckerberg as delusional, he's shown a talent for using others' ideas and making them profitable under Facebook. The success of Instagram and WhatsApp is proof. Google+ is nowhere to be seen anymore.
As for Mastodon, underestimating Meta's potential threat, particularly federating with Mastodon (this can be seen as "easy hosting" of something like Mastodon), might be a mistake. Even without originality, they have the resources to cause significant disruption.
I think what's different this time is that Zuckerberg has finally ran out ideas to steal, what Zuck is truly good at is taking a good idea amd wringing every drop of money and data out of the user for ads at the expense of missing good, honest opportunities over the decades. Off the top of my head, how do you think it would have went if Facebook started using the momentum of the popularity of Facebook games to start publishing high quality original games in the 2010s to lock people in instead of going Meta 10 years too late out of desperation?
As for Instagram and Whatsapp, I think that's more on Google fumbling literally everything they touch during Sundar Pichay (Yes, I think even less of Google than Facebook, they are the modern 90s Microsoft) than Facebook.
That's the ultimate issue with basing your company entirely off stealing ideas and internet ads, eventually you get so lazy and addicted to the easy money you forgot how to make good things anymore. Zuck couldn't kill TikTok, but a hungry and cornered Bytedance is now coming for Instagram, so he should honestly should be more worried about that right now.
One other thing is that you can't just throw money at things to beat the market leader, you also need to bring something different to the table. Look at Mixer vs Twitch for example.
Threads is not an all an idea but an execution. Twitter abandoned it's value proposition of nobodies being able to shit post non-billionaire elites and threads just relaunched that concept. Way different situation than trying to compete with TikTok since Twitter set itself on fire and made itself unfashionable. Nobody needs to innovate the next Twitter they just need to replace what Twitter took away. The fediverse itself would still seem to service a different demographic from that since shit posting celebs is all normies ever wanted from that platform.
I think that an important part of twitter was the proximity to power through politicians, journalists and celebrities. If threads is good at making those people switch over, then I think a lot of other people will switch over as well. On big part of twitter users is people who love discussing the news and current events and that's much more appealing when you can do it on the same platform as people who are in the news or write the news.
(On the other hand lemmy has Margot Robbie so maybe we're in the race as well?)