Ocarina of Time & Majora's Mask were 40-50 people. If you look at the credits for modern games, they scroll for minutes at light speed. The entire credits are ~100 people on those games.
Some of that is the standard for bugs has changed. Games do still ship with bugs but back in the day the standard was just "be playable to the end and don't crash" Now there's a complex certification process to validate the game's behavior against the system's host OS, and if the game has online features you have to test against cheating and exploits. Check out some of the bugs that speedrunners exploit in older games that let them manipulate the contents of memory, that would be considered insane today. So you need a lot more QA staff than back in the day.