Only in Europe.
Prior to the PS1, home consoles sold poorly in Europe. "Home computers" like the ZX Spectrum, Amiga, and Atari ST were the dominant gaming platforms in the region during the 80s and first half of the 90s. The home computer market collapsed in the mid 90s, allowing consoles to fill the vacuum, which they did in Gen 5. The PS1 became the most popular console that generation in Europe just as it did in North America and Japan. It sold as many or more units as the NES, SNES, Master System, and Mega Drive combined in the region.
But in the U.S. and Japan, home consoles were already firmly established as a presence back in the 8-bit era (the Atari 2600 was also very successful in the U.S., but considering the console market imploded in 1983 it's hard to say consoles were well-established at the time). The PS1 sold only about on par with the NES in those countries. It sold slightly less than the NES in Japan according to Famitsu. In the U.S. there's some uncertainties with the sales data, but the PS1 either sold slightly more or slightly less than the NES. PlayStation itself became a mainstream brand with the PS1, but it did not make home consoles the standard in North America or Japan. Home consoles had been the standard for two generations prior.
The only reason the PS1 became the first home console to sell over 100 million units it because it was the first console to be mass-adopted by European gamers.