AMD wasn't really a consideration but for budget until they launched the Athlon in the late 90s. The success of Athlon was as much about Intel's fumble with Netburst as it was with Athlon being a solid competitor.
It took Intel almost a decade to roll out Core and in that time AMD failed to capture the market despite making tremendous gains and legitimizing itself.
Ultimately AMD fumbled with the Bulldozer/Excavator lines of CPUs and lost almost everything they had gained.
The reasons AMD couldn't capture the market are complex but the short answer is that Intel influences every aspect of a computer from software, to compilers, to peripherals, to firmware.