The one-handed tree does get better, but not until you've sunk more perks in. Right now at level 15 you're basically still in the tutorial phase for melee. The early perks are pretty weak - they're mostly just damage multipliers that don't feel like much when you're comparing a sneak dagger hit to a sneak arrow.
Where it clicks is when you get access to the perks that add actual effects. There's one that lets you disarm enemies, one that causes bleeding, stuff like that - those actually change how combat feels. Plus if you invest in smithing you can upgrade that steel dagger to something better pretty quick, which helps way more than people realize.
That said, if you're enjoying the bow and the dagger just feels like a backup, honestly there's nothing wrong with staying ranged the whole game. Stealth archer works fine solo. The melee stuff is more fun if you want variety or get caught, but it's not like you're gimping yourself by ignoring one-handed. Just keep leveling it passively while you sneak and bow, and by level 30-40 you'll have enough perks that a backstab actually feels lethal instead of ticklish.
On Switch you're also stuck with vanilla, so no overhaul mods that could rebalance the early perks anyway. Just push through and you'll get there.
