The pros didn't really practice shooting threes back then. Now anyone can do it if you practice it enough. Nikola Jokić can shoot threes. He wouldn't be able to do that 20 years ago.
Back then, Reggie Miller and Ray Allen were the big three point shooters in the league. I thin when Reggie Miller retired he was the NBA leader, then Ray Allen surpassed him. Currently, Allen is #2 on the list, and Reggie Miller is #4. So even with the three point craziness today, they are still up there.