In case this is an honest question:
Ripple and Stellar are popular examples of networks that can process lots of transactions fast and cheap, but in my perspective they're both examples of tech bros finding a new playground - especially true for Ripple.
But there are other gems such as https://nano.org/en, which come to mind. It's true open source, was distributed for free, has transactions without a fee and can process hundreds of transactions per second with a tiny ecological footprint.
Yeah, I know, it sounds too good to be true, but if you have a closer look, it just is good.
Monero does not exactly have the capacity for hundreds of transactions per second, but offers a degree of privacy that's awesome.
And then there's the OG Ethereum, which in fact can process lots of transactions per second often at a quite low cost, which offers a Turing complete smart contract language.
You see, there are at least some alternatives, which offer lots of fast and cheap or even feeless transactions or transactions with other benefits, wuch as privacy.
The development didn't stop with the "train wreck waiting to happen Bitcoin".
I'm glad Bitcoin created the whole crypto sphere.
At the same time I'm dumbstruck how most of the whole sphere is just a soulless, useless money grab.
It's hard to find the projects that aren't, but they are here, hidden in a pile of shit.
You might realize that the projects I listed are more or less random examples, which mostly have one thing in common: they've been around for quite some time.

Nano, Atto and a few other payment-focused coins

Ethereum

Nano has one of the lightest nodes, making it quite eco friendly. And Atto's node can run on a 1 GB VPS (the minimum requirements are here)