I planted the same tomato variety in a raised bed and directly in the ground, ten feet apart, same sun exposure, same watering schedule. The raised bed plants fruited nine days earlier, thanks to soil that warmed up faster in spring, but needed watering almost twice as often by August.
Ground-planted tomatoes caught up in total yield by the end of the season and needed noticeably less intervention once established. The raised bed’s real advantage showed up in weed control, maybe fifteen minutes of weeding all season versus a weekly fight in the ground rows.
If your soil is decent already, ground planting saves water. If your soil is poor or compacted, the raised bed pays for itself in the first season.