We had a similar issue in our place, except it was a chunky timber banister that made the whole hallway feel like a tunnel. Wife hated how dark it was so we ended up swapping it for a glass balustrade. Ours wasn’t a simple straight run either, had a weird landing and a couple of curved steps that made measuring a nightmare. Went with a company that does bespoke home glass, link: home glazing solutions and they actually sent someone out twice to double check the angles before cutting anything. Difference was insane, light just floods through now.