It turned out that in 1999, Elo produced and sold special versions of the iMac G3 with a touchscreen through Apple’s reseller program. They were used as kiosk machines. The author of the YouTube channel Michael MJD got hold of a prototype of such a computer and showed it on video.
These versions of the iMac G3 were equipped with Elo’s proprietary iTouch touch interface, which uses surface acoustic waves to detect where a user touches the screen with their finger.
By the way, a few years ago, the head of Apple’s hardware development department assured that the Mac is fully optimized for keyboard and mouse, and the company is not going to change this. However, Bloomberg reports that Apple has started working on touchscreens for Macs, and the MacBook Pro with OLED display may become the first Mac with a touchscreen in 2025.