R50 Upgrade: Sigma 17-40 f/1.8 vs. Sigma 18-50 f/2.8 vs. 28-70 f/2.8 for indoor kids/street?

Hi everyone! I’ve been shooting with the R50 and the 18-45mm kit lens for a year. I travel a lot and focus on street/kids, but I absolutely hate the kit lens indoors—everything is just way too grainy in low light.

I don't do video, so no IBIS isn't an issue. Also, weight/bulk isn't a big concern for me—I’m currently stuck between these three options:

1. Sigma 17-40mm f/1.8 DC Art (RF Mount): This seems like the ultimate low-light fix. It’s a constant f/1.8, so I’m essentially replacing my kit lens with the light-gathering power of three fast primes.

2. Sigma 18-50mm f/2.8 DC DN (RF Mount): The more compact and affordable alternative. I’m wondering if f/2.8 is enough of a leap from the kit lens to actually clean up the noise in a dim living room, or if I’ll just regret not going faster.

3. Canon RF 28-70mm f/2.8 IS STM: A "future-proof" choice for Full Frame later, but it would be a ~45-112mm equivalent on my R50. I’d have to carry the kit lens for wide shots.

Given that I don't mind a heavier setup, is the 17-40mm f/1.8 the clear winner here? Or is future-proofing with the 28-70mm actually a smart move for an APS-C shooter?