For those that don't mind paying a bit more there's of course non-DIY solutions that do the same. We went all out and bought a Quooker with our new kitchen: boiling water, cold and filtered water, and carbonated water. Of course it helps that here in the Netherlands, the tap water is basically mineral water.

It's a luxury, but we really love it.

Depending on your exact location it's only like mineral water if you don't mind the limescale.

For the articles above making your own hop water is very easy as well. Just soak some hops in room temp water and throw in fridge overnight. Toss in a little lemon juice, and carbonate. Could even use tea.

Will need to play with the amount of hops, but it's cheap.

Do you not have SodaStream in the US?

A larger tank (filling a 5lb tank off a 50lb tank) uses less time and money than exchanging 1lb canisters. It also has the ancillary benefit of supporting local welding supply companies and brewing stores than foreign corporations and big box stores.

I don't know if I'd want to consume anything from a welding shop.

This is a valid concern. I did years of homebrew beer before I learned there is food grade and non-food grade CO2. You should not be using non-food grade to carbonate water or beer. It can have oils and other residue in it.

you can also wrench open a sodastream canister, buy a 3lb block of dry ice from a grocery store for $4, crush it, and pour the crumbs into the canister. Youtube has tutorial videos.

The article alleges that sodastreams produce weaker fizz than commercial carbonated water.

I personally haven't found that to be the case, but it seems like there's dozens of sodastream models and maybe I happened on a good one.

My experience is the opposite across a range of models, I always go relatively conservative otherwise it feels like drinking nails.