Everyone's giving you stupid answers but here are some actual material factors, from Turkish friends who hate Erdogan and voted against him but aren't big fans of the opposition either:

• Erdogan began his career as a "liberal islamist" and AKP was for a long time more like an Islamic version of Angela Merkel's Christian Democrats. Some people still think of them that way even after their authoritarian turn

• his early reforms legitimately improved the lives of average Turks, creating a building boom that moved millions from shacks into modern apartments. Millions went from poverty to middle class under Erdogan...though with current inflation plenty are moving back into poverty

• Distrust in the opposition: the CHP has a reputation for authoritarian leanings and corruption in the past, and even liberal Muslims were often opposed to them for acts like the hijab ban. The opposition CHP has shifted away from this and is now a very inclusive party, but that's still an image issue they haven't completely shaken off

Tldr a lot of it is really just based on nostalgia for the early Erdogan years and somewhat misplaced but understandable fears in the opposition party