I know Jerez is an easy train ride from Seville. Places like Ronda seems like 2+ hour bus ride. Are there paid tours from Seville?
I have no knowledge about tours, but besides Jerez you also have Cádiz and Córdoba as train-based day trip options from Seville.
There is a high-speed train from Seville to Cordoba. It takes 48 minutes.
I googled "day trips from Seville" and found many possibilities including Cordoba, Ronda and some white villages. There may have been others, but off the top of my head, that's what I remember.
In 2017, we used Naturanda for a day-trip from Seville to Jerez de la Frontera and Cadiz. The "small group" consisted of us and one other amiable couple. I would definitely use them again.
Italica and Carmona are nice visits close by.