It really depended on what you were doing, and how comfortable you were in the terminal. Even using Ubuntu you still had some terminal use required, and for gaming it just was not there yet at all. It’s definitely been a viable alternative for standard users for at least 7 years, and gaming got good about 5 years ago.

Source: Gamer who started dual-booting Linux 15 years ago, and stopped dual-booting Windows about 4 years ago.