Been to both.
2 different vibes so depends on what you want Cabo - Mexican party vibe, lots of beach vendors, rougher waters, strong currents, great fishing, not so great snorkeling, great golf, lots of bars
T&C - Grace Bay is one of the top 10 beaches in the world, powder sand, Caribbean laid back vibe, not much nightlife, great snorkeling, more of a stay at your resort and hang at the beach place, the airport is vile - small hot and cramped.
21 year old me would choose Cabo. Me today would go to T&C in a second - and will be next year.