OP here, it's true. Actually, Pi-hole relies on dnsmasq to resolve, block and cache DNS requests. However, Pi-hole with its friendly web interface allows people with less technical knowledge to block ads, trackers and C2 servers.
Pi-hole can block websites on HTTPS. The only inconvenience is that you will not get an informative 'block page', but you get a standard browser-generated error page instead. Pi-hole does not generate SSL certificates on the fly like intercepting proxies do.
An RPi 3 boards about $60AUD, but once you add a PSU, HDMI cable, microSD card and case you're looking at about $100 yeah. We pay outrageous prices for tech, there's even been a parliamentary enquiry into it. It's the price you pay for sunshine and nice beaches.
OP here. Pi-hole only resolves DNS, your throughput will not be affected. Actually, it makes your Internet browsing faster as Pi-hole caches your DNS requests. We run Pi-hole on Raspberry Pi 1 & NBN and it just works fine.
OP here. Pi-hole was designed to run on a home network, so the DNS service is wide-open to everyone. The admin panel is also listening on the same interface as the DNS server. Even unauthenticated users can access the web panel and view some basic stats without logging in.
The general recommendation is setting up OpenVPN (or similar) and make Pi-hole listen on the tunnel interface.
I've been running it at home for about a month and I find it no less cumbersome to a browser plugin. The whitelists are permanent, and if you think it's blocking something, you can look at the block list log & whitelist. As a last resort you can also disable it temporarily.