GrapheneOS is a harden Android that gives you more control over your phone and its data. It's not the only FOSS variant based on AOSP and works only on Google's Pixel hardware as of today for security reasons.
I've been running it for years now and I honestly like it very much.
The core of Android is open source and named AOSP for short, it is built on top of the Linux kernel which is also free and open source.
However Google have made AOSP not usable by abandonning most of the free app in favor of their own proprietary apps such as Google Messenger, Goole Photos etc...
That's why community project like LineageOS builds their own apps to make them usable instead of the old deprecated ones.
Brands like Samsung, OnePlus, etc.. are not building from AOSP but rather paying a licence fee to Google so they can use the Google Services that are almost necessary to modern Android.
OP is running GrapheneOS which is a Free and Open Source Operating System based on AOSP.
I pay almost weekly using either Bitcoin's Lightning Network or Monero. I mainly buy food, snacks, hardware and online services.
I never used an online casino such as Binance or Kraken, therefore I don't use them as crypto-bank nor do I do trading (never did), I often buy on centralized exchange but it goes straight to my wallet. As of today I never sold to cashout.
Take Nigeria, India, Peru or Vietnam as exemple, many people there don't have bank accounts, however they have a smartphone connected to the internet. Those country have a high percent of people using crypto. Why ?
Because thanks to that technology they are able to be there own bank simply by downloading an app. Some are not their own bank but have a banking experience. Most of them got the opportunity to own american dollar that way thanks to USDT and USDC stablecoin. It's closer to what they know the USD in cash. However there is many people realizing that Bitcoin volatility isn't bad because their local currency have worse volatility going down over the past 15 years where Bitcoin is going the opposite direction.
We started to see offchain system that don't need an onchain transactions to transacts, it does not have the same level of security as the public ledger but what does that mean is that in the future we will probably not transact daily on the blockchain but on second layer that communicate to the base layer.
Blockchain is inneficient by design but it allows us to have a decentralized immuable and neutral ledger, we will scale by other mean.
Money has no price, money as an ancient pre-historic technology is a way to build trust between people that don't interact often together and thus need a language to express the labour of their work or the value of their properties. Bitcoin is not the money of the internet but rather the internet of money as stated by Andreas Antonopoulos.
I personnaly don't use OpenVibe as I tend to avoid proprietary software on personnal device but I like the idea of having multiple protocoles or services in one feed.
I think nostr has some amazing feature and it's something really interesting to see evolving but the fediverse has a much bigger and diverse user-base which is important to me. Ditto is making the two bridgeable so I think it's a bright future for distributed social networks (not social media :D)
I use it on desktop, despite some bugs from time to time I really enjoy the experience and slick design !
It's still in early alpha so honestly I am impressed !
Consider paying the one-time fee if you enjoy the experience, it will remove ads and tracking. You can also consider other client such as Voyager which is FOSS.
I'm not running a Synapse server myself so I can only speak on behalf of people I know who are. From what they told me they love the matrix protocol but it's not the same for the synapse implementation. A non-federated server can have somewhat great performance but a federated one was not worth it for them so they decided to switch to another alternative.
They are not running for thousands of users more something like 40 I would say and while I don't know their server specs, I assume it's not a potato though.
Because everyone miss the old OpenWeb ! We don't like closed API ! We don't like opaque and imposed algorithmes ! We don't like centralized closed plateform ! We don't want to be enslave to create data. We don't want their addicting mechanism, digitalizing heroin. We don't want blockchains to record every interractions we have !
All we want is Web0 ! And the Fediverse might be part of this better Open Web.
I have not tested all of them myself and not sure it exactly correspond to your needs but here are a few options :