Part of the issue is old games were designed for the shitty 13-15" CRTs of the day. They had a natural amount of antialiasing from phosphor bleed and dot pitch

Part of the issue is old games were designed for the shitty 13-15" CRTs of the day. They had a natural amount of antialiasing from phosphor bleed and dot pitch of the shadow mask. Game art often took advantage of these limitations. You see the same issues with old console games on emulators. While some people like the "pixelated" look you see with default settings, it's not how the games actually looked on a CRT.