We just replaced them all with cacti. There’s a dead one on the window sill in the living room I forgot to water that still looks pretty good!

You need one for each plant, unlike a Roomba, but self-watering planters are a thing (and two dozen of them are probably cheaper than one robot)

Not exactly comparable to a Roomba, but there is the Farmbot: https://farm.bot/

Ops, you said house plants. I guess my suggestion isn’t suitable for you, but might be interesting for other people so I’ll keep it here.

I feel that you need a hydroponics setup instead

There's an old time trick where you put a bottle with a wick (like a woolen thread) from the bottle into the house plant. There's pots with a system like that built in; water reservoir at the bottom, wick going to the top part.

I'm sure there's more expensive options involving timers and internet-of-shit as well.

I am actually looking into building something that helps with watering house plants.

Is your problem that you forget to water them, overwater them or just the sheer amount it takes to water your plants because you have so many? (Or maybe something else?)

Have a roomba-like fill a dog-bowl like resevoir then use an electric pump to circulate to nearby plants? Or just fill the resevoir manually?

Seems nifty.

Can’t you just use those bulb things?